July 5, 1991 was one of the most important days of my life. My mom was hosting a get-together at our family’s favorite vacation spot in Hood Canal, WA. One of her friends had invited Warren Buffett, and I immediately hit it off with him, kickstarting a relationship that would, among other things, lead to the creation of the Gates Foundation.

But Warren wasn’t the only legend in the room. I remember him introducing me to his old friend Katharine Graham, one of the most well-respected newspaper publishers in the world. Even after all these years—and after her death in 2001—I still treasure the friendship I began with Kay that day.

Kay is best known for leading the Washington Post through the Watergate crisis, but her remarkable story goes way beyond her fights with the Nixon White House. That story is told in her riveting memoir Personal History, which came out in 1997—just a few years before she passed away—and won the Pulitzer Prize for Biography.

Kay’s father purchased the Washington Post and saved it from bankruptcy when she was a teenager. In 1946, he made Kay’s husband, Philip Graham, the publisher of the paper. Although this decision sounds strange today—Why would you hand over the family business to your son-in-law instead of your own child?—the thought of putting a woman in charge was unthinkable in that era. “It never crossed my mind that he might have viewed me as someone to take on an important job at the paper,” she writes. Kay was expected to devote her life to being a good wife and mother.

But life with Phil wasn’t easy. He suffered from bipolar disorder at a time when treatments for mental illness were crude and ineffective. The chapters about his mental decline are devastating. Kay describes how Phil had to be sedated after suffering from a manic episode at a publishing conference. A few months later, he dies by suicide during a stay at the family’s country home. Kay is the first person to find his body.

While she was struggling with grief, Kay found herself thrust into a new role: president of the Washington Post Company and the publisher of a major national newspaper. That isn’t an easy job under any circumstances, but several of Kay’s male colleagues made it harder than it needed to be. “I didn’t blame my male colleagues for condescending—I just thought it was due to my being so new,” she writes. “It took the passage of time and the women’s lib years to alert me properly to the real problems of women in the workplace, including my own.”

Still, Kay internalized some of the skepticism, and she is pretty harsh on herself throughout the book. She blames herself for Phil’s suicide and describes her business acumen as “abysmally ignorant” when she takes over the Post. I understand her impulse to be critical of her younger self—I often felt frustrated by how I acted as a kid when I was writing my own memoir, Source Code. But it can be difficult to read at points in Personal History. I wish Kay knew how special she was.

Her story is a powerful reminder that strong leaders don’t always come in the form you expect. What Kay sees as weaknesses end up becoming her strengths. Because she didn’t know much about the newsroom when she took over in 1963, she asked a lot of questions. A more experienced publisher might have come into the job with preconceived notions about how to run things—but Kay listened to her new colleagues, and she took the time to learn how they worked. That trust in her people would pay off years later during the Watergate scandal.

I was a teenager during the Watergate years, and I remember reading about it in the paper. Many people focus on two specific events when they talk about Watergate: the break-in at the Democratic National Committee in June 1972, and President Nixon’s resignation in August 1974 after secret recordings revealed his administration’s involvement in the burglary and subsequent cover-up. But during the more than two years between those two points, the Washington Post reported relentlessly on the scandal.

Nixon himself tried to bully them into giving up, but Kay stood by her newsroom. She protected their editorial independence, never asking her reporters to censor or soften their reporting. At one point, John Mitchell—the chair of Nixon’s re-election campaign and former Attorney General—told a Post reporter that Kay was going to get a certain part of her anatomy “caught in a big fat ringer.” She read about it in the paper the next day.

Kay risked the company’s reputation and financial health to protect journalistic integrity, even in the face of potential lawsuits and calls to discredit the paper. The Post almost folded at one point when the Nixon administration threatened to pull the broadcasting licenses for several TV stations owned by the Washington Post Company. (Despite being the namesake of the company, the Washington Post itself was not profitable at the time. The business relied on local broadcast stations to stay afloat.)

This is where Warren enters the story. He believed the Washington Post was undervalued, and in 1973, Berkshire Hathaway bought a 10 percent ownership share—enough to keep the company going while making sure that Kay remained in control. He eventually became a trusted advisor and a close friend to Kay, which I saw firsthand years later in Hood Canal.

Warren has always hated that Kay was left out of the movie All the President’s Men, which came out just two years after Nixon resigned and received great critical acclaim. Without her leadership and bravery, the Watergate scandal might have faded into obscurity. Fortunately, the film The Post gave Kay her proper due. Meryl Streep was even nominated for an Oscar for playing her.

There is so much to Kay’s story—including her time with President Kennedy, the Pentagon Papers, and the pressmen’s strike—that I cannot mention all of it here. If you want to learn even more about her incredible life, I recommend starting with the new documentary Becoming Katharine Graham before reading Personal History.

Diving deep into Kay's extraordinary life is well worth your time. Her story offers more than just insights into a fascinating chapter of American history—it also reveals valuable lessons about courage, leadership, and finding strength in vulnerability.

If you’re a big reader, you can probably point to a book or two that changed the course of your life. For me, it was a 1997 New York Times column by Nicholas Kristof about diarrhea, which was killing three million kids a year.

At the time, I had wealth—and knew I planned to give it away—but no clear mission. Nick’s article gave me one. I faxed it to my dad with a note: “Maybe we can do something about this.”

That ended up setting the direction for what became the Gates Foundation. It didn’t just give us a what—it gave us a how. Nick’s reporting showed us that the biggest challenge in global health isn’t always discovering new breakthroughs. Often, it’s making sure the tools we already have—vaccines, medicines, bed nets, or oral rehydration therapies for rotavirus—reach every child, no matter where they’re born.

Reading Nick’s new memoir, Chasing Hope, brought me back to that moment and showed me how it fit into the bigger story of his life. The book is a deeply personal account of a life spent documenting injustice and refusing to look away, whether it’s genocide in Darfur, refugee camps in Sudan, or the streets of his hometown in rural Oregon.

Nick’s impulse to go where the suffering is, and to make people care, has defined his career. He’s reported from more than 150 countries, covering war, poverty, health, and human rights. He and his longtime collaborator and wife, Sheryl WuDunn, won a Pulitzer Prize for their work. Together and individually, they’ve brought injustices around the world into view for millions of readers.

But Chasing Hope isn’t just a greatest-hits collection of his past reporting. It’s the story of how someone becomes Nick Kristof. He writes about growing up on a sheep and cherry farm in Oregon, driving tractors as a teenager, and nearly becoming a lawyer before deciding on journalism. He also reflects on the toll his career has taken on him, his family, and his capacity for hope.

I’ve known Nick for many years now, and I’ve admired his work since that 1997 rotavirus column. On paper, we don’t seem all that similar. He’s a journalist, I’m a technologist; he tells stories, I talk numbers. But reading Chasing Hope, I was struck by what we have in common: growing up in the Pacific Northwest, learning about the value of service from our parents, thinking globally.

We both attended Harvard and left early—me because I dropped out, him because he graduated in three years before heading to Oxford as a Rhodes Scholar. But neither of us ever stopped learning. I think we both believe the world’s pretty interesting if you remain a student.

Nick’s curiosity didn’t come out of nowhere, and neither did his sense of purpose. His mother was an art history professor and a civic leader who helped influence local politics. His father, a political science professor who fled both Nazism and communism, believed deeply in education and the responsibilities that come with freedom. That kind of upbringing left a mark on him and shaped the kind of journalist he became.

Over decades, he’s built a career reporting on crises that are often ignored because they happen in far-off places, far from centers of power. In Chasing Hope, he recounts his experiences chronicling river blindness in Ethiopia, maternal mortality in Cameroon, and malaria in Cambodia. Through the foundation, I mobilize science, data, and funding to address many of the same global challenges Nick reports on. Our approaches are different, but the underlying questions we ask (and try to answer) are the same: Why are some lives valued less than others? And how can we use the tools we have—information, resources, attention—to close that gap?

Nick has an admirable commitment to nuance, especially when it comes to hard subjects like China. Nick lived there for years, speaks Mandarin, and understands the country in a way most Western commentators don’t. I’ve always appreciated his ability to go beyond the headlines—and focus not just on what’s going wrong, but on what’s changing and why it matters.

Nick is also an optimist, which might sound strange given the kinds of suffering he writes about. But his work is grounded in a belief I share: The right data—or the right story—can move people to act. As Nick puts it, “A central job of a journalist is to get people to care about some problem that may seem remote.” People, when given the chance, want to make things better. Progress, while never guaranteed, is possible.

That optimism feels especially important, if increasingly difficult, right now. Isolationism is on the rise around the world, and governments are cutting back on foreign aid at the very moment when we should be doing more, not less. Millions of lives are at stake. Nick’s work reminds us what’s possible when we care about people beyond our own borders—and what happens when we don’t.

Chasing Hope made me think a lot about what kind of person chooses to run toward the hardest problems—and keep going back until they’re solved. It also made me think the world would be a much better place if there were more Nick Kristofs. In the meantime, we’re lucky to have this one.

I’ve always prided myself on my ability to teach myself things. Whenever I don’t know a lot about something, I’ll read a textbook or watch an online course until I do.

I thought I was pretty good at teaching myself—until I read Tara Westover’s memoir Educated. Her ability to learn on her own blows mine right out of the water. I was thrilled to sit down with her recently to talk about the book.

Tara was raised in a Mormon survivalist home in rural Idaho. Her dad had very non-mainstream views about the government. He believed doomsday was coming, and that the family should interact with the health and education systems as little as possible. As a result, she didn’t step foot in a classroom until she was 17, and major medical crises went untreated (her mother suffered a brain injury in a car accident and never fully recovered).

Because Tara and her six siblings worked at their father’s junkyard from a young age, none of them received any kind of proper homeschooling. She had to teach herself algebra and trigonometry and self-studied for the ACT, which she did well enough on to gain admission to Brigham Young University. Eventually, she earned her doctorate in intellectual history from Cambridge University. (Full disclosure: she was a Gates Scholar, which I didn’t even know until I reached that part of the book.)

Educated is an amazing story, and I get why it’s spent so much time on the top of the New York Times bestseller list. It reminded me in some ways of the Netflix documentary Wild, Wild Country, which I recently watched. Both explore people who remove themselves from society because they have these beliefs and knowledge that they think make them more enlightened. Their belief systems benefit from their separateness, and you’re forced to be either in or out.

But unlike Wild, Wild Country—which revels in the strangeness of its subjects—Educated doesn’t feel voyeuristic. Tara is never cruel, even when she’s writing about some of her father’s most fringe beliefs. It’s clear that her whole family, including her mom and dad, is energetic and talented. Whatever their ideas are, they pursue them.

Of the seven Westover siblings, three of them—including Tara—left home, and all three have earned Ph.D.s. Three doctorates in one family would be remarkable even for a more “conventional” household. I think there must’ve been something about their childhood that gave them a degree of toughness and helped them persevere. Her dad taught the kids that they could teach themselves anything, and Tara’s success is a testament to that.

I found it fascinating how it took studying philosophy and history in school for Tara to trust her own perception of the world. Because she never went to school, her worldview was entirely shaped by her dad. He believed in conspiracy theories, and so she did, too. It wasn’t until she went to BYU that she realized there were other perspectives on things her dad had presented as fact. For example, she had never heard of the Holocaust until her art history professor mentioned it. She had to research the subject to form her own opinion that was separate from her dad’s.

Her experience is an extreme version of something everyone goes through with their parents. At some point in your childhood, you go from thinking they know everything to seeing them as adults with limitations. I’m sad that Tara is estranged from a lot of her family because of this process, but the path she’s taken and the life she’s built for herself are truly inspiring.

When you meet her, you don’t have any impression of all the turmoil she’s gone through. She’s so articulate about the traumas of her childhood, including the physical abuse she suffered at the hands of one brother. I was impressed by how she talks so candidly about how naïve she once was—most of us find it difficult to talk about our own ignorance.

I was especially interested to hear her take on polarization in America. Although it’s not a political book, Educated touches on a number of the divides in our country: red states versus blue states, rural versus urban, college-educated versus not. Since she’s spent her whole life moving between these worlds, I asked Tara what she thought. She told me she was disappointed in what she called the “breaking of charity”—an idea that comes from the Salem witch trials and refers to the moment when two members of the same group break apart and become different tribes.

“I worry that education is becoming a stick that some people use to beat other people into submission or becoming something that people feel arrogant about,” she said. “I think education is really just a process of self-discovery—of developing a sense of self and what you think. I think of [it] as this great mechanism of connecting and equalizing.”

Tara’s process of self-discovery is beautifully captured in Educated. It’s the kind of book that I think everyone will enjoy, no matter what genre you usually pick up. She’s a talented writer, and I suspect this book isn’t the last we’ll hear from her. I can’t wait to see what she does next.

I’m a longtime fan of Comedy Central’s The Daily Show. When Jon Stewart stepped down as host in 2015, I was sad to see him go. I was also worried for his replacement, Trevor Noah, a South African comedian. Stewart’s style is so unusual that I didn’t see how anyone could fill his shoes—especially someone like Noah, who describes himself as an outsider. As popular as Noah was in South Africa, I didn’t know whether his humor would connect with American audiences.

I’m happy to report that I was wrong. Millions of viewers—myself included—are tuning in to The Daily Show because Noah’s show is every bit as good as Stewart’s. His humor has a lightness and optimism that’s refreshing to watch. What’s most impressive is how he uses his outside perspective to his advantage. He’s good at making fun of himself, America, and the rest of the world. His comedy is so universal that it has the power to transcend borders.

Reading Noah’s memoir, Born a Crime, I quickly learned how Noah’s outsider approach has been honed over a lifetime of never quite fitting in. Born to a black South African mother and a white Swiss father in apartheid South Africa, he entered the world as a biracial child in a country where mixed race relationships were forbidden. Noah was not just a misfit, he was (as the title says) “born a crime.”

In South Africa, where race categories are so arbitrary and yet so prominent, Noah never had a group to call his own. As a little boy living under apartheid laws, he couldn’t be seen in public with his white father or his black mother. In public, his father would walk far ahead of him to ensure he wouldn’t be seen with his biracial son. His mother would pose as a maid to make it look like she was just babysitting another family’s child. On the schoolyard, he didn’t fit in with the white kids or the black kids or the kids who were “colored” (the term used in South Africa to describe people of mixed race).

But during his childhood, he quickly discovered that there’s a freedom that comes with being a misfit. A polyglot who speaks English, Afrikaans, Xhosa, Zulu, Tsonga, Tswana, as well as German and Spanish, Noah used his talent for language to bounce from group to group and win acceptance from all of them. One of my favorite stories in the book involves Noah walking down the street when he overhears a group of men speaking in Zulu about how they were plotting to mug “this white guy.” Noah realizes they were referring to him. Noah spins around and announces in perfect Zulu that they should all mug someone together. The Zulu men are startled that Noah speaks Zulu and a tense situation is defused. Noah is immediately accepted as one of their own.

Again and again throughout his childhood, he discovered that language was more powerful than skin color in building connections with other people. “I became a chameleon,” Noah writes. “My color didn’t change, but I could change your perception of my color. If you spoke to me in Zulu, I replied to you in Zulu. If you spoke to me in Tswana, I replied to you in Tswana. Maybe I didn’t look like you, but if I spoke like you, I was you.”

Much of Noah’s story of growing up in South Africa is tragic. His Swiss father moves away. His family is desperately poor. He’s arrested. And in the most shocking moment, his mother is shot by his stepfather. Yet in Noah’s hands, these moving stories are told in a way that will often leave you laughing. His skill for comedy is clearly inherited from his mother. Even after she’s shot in the face, and miraculously survives, she tells her son from her hospital bed to look at the bright side. “’Now you’re officially the best-looking person in the family,’” she jokes.

In fact, Noah’s mother emerges as the real hero of the book. She’s an extraordinary person who is fiercely independent and raised her son to be the same way. Her greatest gift was to give her son the ability to think for himself and see the world from his own perspective. “If my mother had one goal, it was to free my mind,” he writes. Like many fans of Noah’s, I am thankful she did. 

When Paul Hewson was 11, his parents sent him to a Dublin grammar school that happened to have an outstanding boys’ choir. Paul, who later took the nickname Bono, loved singing. His father had a beautiful voice, and Paul thought he might have some of his dad’s talent. But when the principal asked him if he wanted to join the choir, his mom jumped in before he could answer. “Not at all,” she said. “Paul has no interest in singing.”

Bono’s new book, Surrender, is packed with funny, poignant moments like this. Even though I’m a big fan of U2, and Bono and I have become friends over the years—Paul Allen connected us in the early 2000s—a lot of those stories were new to me. I went into this book knowing almost nothing about his anger at his father, the band’s near-breakups, and his discovery that his cousin was actually his half-brother. I didn’t even know that he grew up with a Protestant mom and Catholic dad.

I loved Surrender. You get to observe the band in the process of creating some of their most iconic songs. The book is filled with clever, self-deprecating lines like “Just how effective can a singer with anger issues be in the cause of nonviolence?” And you’ll learn a lot about the challenges he dealt with in his campaigns for debt relief and HIV treatment in Africa. (The Gates Foundation is a major supporter of ONE, the nonprofit that Bono helped start.)

In this passage, he explains how a boy from the suburbs of Dublin became a global phenomenon: “There are only a few routes to making a grandstanding stadium singer out of a small child. You can tell them they’re amazing, that the world needs to hear their voice, that they must not hide their ‘genius under a bushel.’ Or you can just plain ignore them. That might be more effective. The lack of interest of my father, a tenor, in his son’s voice is not easy to explain, but it might have been crucial.” (It also helped that he has, as he later learned from a doctor, freakishly large lung capacity.)

Bono’s loyalty to his bandmates, and their loyalty to him, is pretty incredible. My favorite illustration from the book takes place at a concert in Arizona, when the band was urging the then-governor to uphold the national MLK Day holiday in his state. U2’s security team picked up a credible threat to Bono’s life if the band played their Martin Luther King tribute “Pride (In the Name of Love).” “It wasn’t just melodrama,” he writes, “when I closed my eyes and sort of half kneeled to disguise the fact that I was fearful to sing the rest of the words.” When Bono opened his eyes, he saw that bassist Adam Clayton had moved in front of him to shield him like a Secret Service agent. Fortunately, the threat never materialized.

There’s another factor that explains the band’s tight bonds: They share the same values. All four of them are passionate about fighting poverty and inequity in the world, and they’re also aligned on maintaining their integrity as artists. I learned this the hard way. When Microsoft wanted to license U2’s song “Beautiful Day” for an ad campaign, I joined a call in an attempt to persuade the band to go for the deal. They simply weren’t interested. I admired their commitment.

While Bono never got lost in drugs or alcohol, he acknowledges that stardom gave him a big ego. He also says that he had a “need to be needed.” His key to survival was embracing the concept of spiritual surrender, as the title of the book suggests. He eventually came to see that he’d never fill his emotional needs by playing for huge crowds or being a global advocate. His faith in a higher power helped him a lot. So did his wife, Ali. He writes that when his mom died during his childhood, his home “stopped being a home; it was just a house.” Ali and their four children gave him a home once again.

Bono writes that his surrender is still incomplete. He’s not going to retire anytime soon, which is great news and not just for U2 fans. After the past few years, the field of global health—one of his chief causes—needs an injection of energy and passion. Bono’s unique gifts are perfectly suited to that mission.

I was twenty when I gave my first public speech. It was 1976, Microsoft was almost a year old, and I was explaining software to a room of a few hundred computer hobbyists. My main memory of that time at the podium was how nervous I felt. In the half century since, I’ve spoken to many thousands of people and gotten very comfortable delivering thoughts on any number of topics, from software to work being done in global health, climate change, and the other issues I regularly write about here on Gates Notes.

One thing that isn’t on that list: myself. In the fifty years I’ve been in the public eye, I’ve rarely spoken or written about my own story or revealed details of my personal life. That wasn’t just out of a preference for privacy. By nature, I tend to focus outward. My attention is drawn to new ideas and people that help solve the problems I’m working on. And though I love learning history, I never spent much time looking at my own.  

But like many people my age—I’ll turn 70 this year—several years ago I started a period of reflection. My three children were well along their own paths in life. I’d witnessed the slow decline and death of my father from Alzheimer’s. I began digging through old photographs, family papers, and boxes of memorabilia, such as school reports my mother had saved, as well as printouts of computer code I hadn't seen in decades. I also started sitting down to record my memories and got help gathering stories from family members and old friends. It was the first time I made a concerted effort to try to see how all the memories from long ago might give insight into who I am now.

The result of that process is a book that will be published on Feb. 4: my first memoir, Source Code. You can order it here. (I’m donating my proceeds from the book to the United Way.)

Source Code is the story of the early part of my life, from growing up in Seattle through the beginnings of Microsoft. I share what it was like to be a precocious, sometimes difficult kid, the restless middle child of two dedicated and ambitious parents who didn’t always know what to make of me. In writing the book I came to better understand the people that shaped me and the experiences that led to the creation of a world-changing company.

In Source Code you’ll learn about how Paul Allen and I came to realize that software was going to change the world, and the moment in December 1974 when he burst into my college dorm room with the issue of Popular Electronics that would inspire us to drop everything and start our company. You’ll also meet my extended family, like the grandmother who taught me how to play cards and, along the way, how to think. You’ll meet teachers, mentors, and friends who challenged me and helped propel me in ways I didn’t fully appreciate until much later. 

Some of the moments that I write about, like that Popular Electronics story, are ones I’ve always known were important in my life. But with many of the most personal moments, I only saw how important they were when I considered them from my perspective now, decades later. Writing helped me see the connection between my early interests and idiosyncrasies and the work I would do at Microsoft and even the Gates Foundation.

Some of the stories in the book were hard for me to tell. I was a kid who was out of step with most of my peers, happier reading on my own than doing almost anything else. I was tough on my parents from a very early age. I wanted autonomy and resisted my mother’s efforts to control me. A therapist back then helped me see that I would be independent soon enough and should end the battle that I was waging at home. Part of growing up was understanding certain aspects of myself and learning to handle them better. It’s an ongoing process.

One of the most difficult parts of writing Source Code was revisiting the death of my first close friend when I was 16. He was brilliant, mature beyond his years, and, unlike most people in my life at the time, he understood me. It was my first experience with death up close, and I’m grateful I got to spend time processing the memories of that tragedy.

The need to look into myself to write Source Code was a new experience for me. The deeper I got, the more I enjoyed parsing my past. I’ll continue this journey and plan to cover my software career in a future book, and eventually I’ll write one about my philanthropic work. As a first step, though, I hope you enjoy Source Code.

In the introduction to his latest book, How to Feed the World, Vaclav Smil writes that “numbers are the antidote to wishful thinking.” That one line captures why I’ve been such a devoted reader of this curmudgeonly Canada-based Czech academic for so many years. Across his decades of research and writing, Vaclav has tackled some of the biggest questions in energy, agriculture, and public health—not by making grand predictions, but by breaking down complex problems into measurable data.

Now, in How to Feed the World, Vaclav applies that same approach to one of the most pressing issues of our time: ensuring that everyone has enough nutritious food to eat. Many discussions about feeding the world focus on increasing agricultural productivity through improved seeds, healthier soils, better farming practices, and more productive livestock (all priorities for the Gates Foundation). Vaclav, however, insists we already produce more than enough food to feed the world. The real challenge, he says, is what happens after the food is grown.

This kind of argument is classic Vaclav—questioning assumptions, forcing us to rethink the way we frame problems, and turning conventional wisdom on its head. His analysis is never about the best- or worst-case scenarios; it’s about what the numbers actually tell us.

And the numbers tell a striking story: Some of the world’s biggest food producers have the highest rates of undernourishment. Globally, we produce around 3,000 calories per person per day—more than enough to feed everyone—but a staggering one-third of all food is wasted. (In some rich countries, that figure climbs to 45 percent.) Distribution systems fail, economic policies backfire, and food doesn’t always go where it’s needed.

I’ve seen this firsthand through the Gates Foundation’s work in sub-Saharan Africa, where food insecurity is driven by low agricultural productivity and weak infrastructure. Yields in the region remain far lower than in Asia or Latin America, in part because farmers rely on rain-fed agriculture rather than irrigation and have limited access to fertilizers, quality seeds, and digital farming tools. But even when food is grown, getting it to market is another challenge. Poor roads drive up transport costs, inadequate storage leads to food going bad, and weak trade networks make nutritious food unaffordable for many families.

And access is only part of the problem. Even when people get enough calories, they’re often missing the right nutrients. Malnutrition remains one of the most critical challenges the foundation works on—and it’s more complex than eating enough food. While severe hunger has declined globally, micronutrient deficiencies remain stubbornly common, even in wealthy countries. One of the most effective solutions has been around for nearly a century: food fortification. In the U.S., flour has been fortified with iron and vitamin B since the 1940s. This simple step has helped prevent conditions like anemia and neural tube defects and improve public health at scale—close to vaccines in terms of lives improved per dollar spent.

One of the most interesting parts of the book is Vaclav’s exploration of how human diets evolved. Across civilizations, people independently discovered that pairing grains with legumes created complete protein profiles—whether it was rice and soybeans in Asia, wheat and lentils in India, or corn and beans in the Americas. These solutions emerged from practical experience long before modern science could explain why they worked so well.

But just as past generations adapted their diets to available resources, we’re now facing new challenges that require us to adapt in different ways. Technology and innovation can help. They’ve already transformed the way we produce food, and they’ll continue to play a role. Take aquaculture: Once a tiny industry, it’s grown over the past 40 years to supply more seafood for the world than traditional fishing—a scalable way to meet global protein demands. The Green Revolution is another example. Beginning in the 1960s, innovations in higher-yielding crops, more effective fertilizers, and modern irrigation prevented widespread famine in India and Mexico. These changes were once seen as unlikely, too.

New breakthroughs could drive even more progress. CRISPR gene editing, for instance, could help develop crops that are more resilient to drought, disease, and pests—critical for farmers facing the pressures of climate change. Vaclav warns that we can’t count on technological miracles alone, and I agree. But I also believe that breakthroughs like CRISPR could be game-changing, just as the Green Revolution once was. The key is balancing long-term innovation with practical solutions we can implement immediately.

And some of these solutions aren’t about producing more food at all—they’re about wasting less of what we already have. Better storage and packaging, smarter supply chains, and flexible pricing models could significantly reduce spoilage and excess inventory. In a conversation we had about the book, Vaclav pointed out that Costco (which might seem like the pinnacle of U.S. consumption) stocks fewer than 4,000 items, compared to 40,000-plus in a typical North American supermarket.

That kind of efficiency—focusing on fewer, high-turnover products—reduces waste, lowers costs, and ultimately eases pressure on global food supply, helping make food more affordable where it is needed most.

How to Feed the World had a lot to teach me—and I’m sure it will teach you a lot, too. Like all of Vaclav’s best books, it challenges readers to think differently about a problem we thought we understood. Growing more and better food remains crucial—especially in places like sub-Saharan Africa, where there simply isn’t enough. But as the world’s population approaches 10 billion, increasing agricultural productivity alone won’t solve hunger and malnutrition. We also need to ensure that food is more accessible and affordable, less wasted, and just as nutritious as it is abundant.

After all, the goal isn’t to make more food for its own sake—it’s to feed more people.

I picked either the best time or the worst time to read Doris Kearns Goodwin’s new memoir. As I finished it, I was also deep in the writing of my first autobiography. On one hand, reading a book as thoughtful and well written as An Unfinished Love Story inspired me to push myself even more as an author. On the other hand, Goodwin sets a daunting example. Trying to write as well as she does is like trying to sing along with Lady Gaga.   

I’m a big fan of Goodwin’s—Team of Rivals is one of my favorite history books ever—so I wasn’t surprised that An Unfinished Love Story was so compelling. It starts with a clever conceit. Doris was married for 42 years to Dick Goodwin, a policy expert and White House speechwriter who played a crucial role in the Kennedy and Johnson administrations of the 1960s. Toward the end of Dick’s life, he and Doris started going through 300 boxes of papers and memorabilia he had collected—an exercise that led them to reopen an old debate about the relative merits of the two presidents, and especially the question of which man deserves more credit for the accomplishments of the Great Society.  

The book is partly about Doris and Dick’s decades-long relationship, and partly about a pivotal time in American history. It works on both fronts.  

I had never heard of Dick Goodwin before I read the book. I did know about Ted Sorensen, who had a major influence on Kennedy’s thinking and speeches; Dick Goodwin, it turns out, was just as important. He helped shape the Great Society, the most dramatic shift in America’s public safety net since Franklin Roosevelt’s New Deal. He was a senior advisor on Bobby Kennedy’s presidential campaign, and many years later, drafted Al Gore’s statesmanlike concession speech after the 2000 election. (Goodwin also led the investigation in the real-life game-show scandal that was the subject of the movie Quiz Show; he’s played by Rob Morrow.) 

The book left me with more admiration for both Kennedy and Johnson. When the Goodwins began the project of going through Dick’s papers, each had clear opinions on the two presidents: Dick was a Kennedy guy who quit the Johnson administration in protest over the Vietnam war and the president’s domineering style, while Doris preferred Johnson’s political savvy and ability to get things done. She worked at the White House during the latter’s administration and became a confidante; after he left office, she went to Texas to help him with his memoir. 

Sadly, the Goodwins’ project was cut short by Dick’s death in 2018. In the end, he and Doris came to see both presidents in a more nuanced way. After reading the book, so did I. Doris takes you behind the scenes so you can watch the two presidents and their teams figure out how to move their agenda forward, recruit good people, and explain their plans to the public. At the same time, she doesn't shy away from the contradictions and flaws in their characters, particularly in LBJ's case.  

Doris’ personal experiences, and her retelling of Dick’s, make the history feel more real. She’s not just reporting on what happened—she can tell you what it was like to be there, using intimate personal details to bring the era to life in a way I hadn’t seen before. In one funny and revealing moment, Johnson complains that Dick Goodwin is getting too much attention from the media—to the point that he tells a reporter that no one by that name even works at the White House. 

I think this book will resonate with a lot of different readers. For one thing, it’s hard to deny the similarities between the 1960s and today—a time of political upheaval, generational conflict, and protests on college campuses. Whether you already know a lot about the ’60s or you’re just dipping your toe into those waters, whether you want a deep dive into the art of political writing or a charming story about a married couple who adored each other, you’ll get it from An Unfinished Love Story.

Growing up, I was always going down rabbit holes to explore whatever caught my interest or captured my curiosity. When I felt restless or bored—or got in trouble for misbehaving—I would disappear into my room and lose myself in books or ideas, often for hours without interruption. This ability to turn idle time into deep thinking and learning became a fundamental part of who I am. 

It was also crucial to my success later on. At Microsoft in the ’90s, I began taking an annual “Think Week,” when I would isolate myself in a cabin on Washington’s Hood Canal with nothing but a big bag of books and technical papers. For seven days straight, I would read, think, and write about the future, interacting only with the person who dropped off meals for me. I was so committed to uninterrupted concentration during these weeks that I wouldn’t even check my email. 

Reading Jonathan Haidt’s The Anxious Generation has made me wonder: Would I have developed this habit if I had grown up with today’s technology? If every time I was alone in my room as a kid, there was a distracting app I could scroll through? If every time I sat down to tackle a programming problem as a teenager, four new messages popped up? I don’t have the answers—but these are questions that everyone who cares about how young minds develop should be asking. 

Haidt’s book, about how smartphones and social media have transformed childhood and adolescence, is scary but convincing. Its premise—that starting in the early 2010s, there was a “great rewiring” of an entire generation’s social and intellectual development—was interesting to me in part because I saw it happen in my own house. When my oldest daughter (a pediatrician who recommended the book to me) was in middle school, social media was present but not dominant. By the time my younger daughter reached adolescence six years later, being online all the time was simply part of being a pre-teen.  

What makes The Anxious Generation different from other books on similar topics is Haidt’s insight that we’re actually facing two distinct crises: digital under-parenting (giving kids unlimited and unsupervised access to devices and social media) and real-world over-parenting (protecting kids from every possible harm in the real world). The result is young people who are suffering from addiction-like behaviors—and suffering, period—while struggling to handle challenges and setbacks that are part of everyday life.  

My childhood was marked by remarkable freedom—something that might surprise people who assume I spent all day glued to a computer indoors. I went hiking on trails that would terrify today’s parents, explored endlessly with neighborhood friends, and ran around Washington D.C. during my time as a Senate page. When I was in high school, Paul Allen and I even lived on our own for a few months in Vancouver, Washington, while working as programmers at a power company. My parents didn’t know where I was half the time, and that was normal back then. While I got hurt on some of these adventures and got in trouble on many others, these experiences were more beneficial than bad. They taught me resilience, independence, and judgment in ways that no amount of supervised, structured activity could replicate. 

It wasn’t all fun and games, but I had what Haidt calls a play-based childhood. Now, a phone-based childhood is much more common—a shift that predated the pandemic but solidified when screens became important tools for learning and socializing. The irony is that parents these days are overprotective in the physical world and strangely hands-off in the digital one, letting kids live life online largely without supervision.  

The consequences are staggering. Today’s teenagers spend an average of six to eight hours per day on screen-based leisure activities—that is, not for schoolwork or homework. The real number might actually be much higher, given that a third of teenagers also say they’re on a social media site “almost constantly.” For the generation Haidt writes about, this has coincided with sharp spikes in anxiety and depression, higher rates of eating disorders and self-harm, plummeting self-esteem, and increased feelings of isolation despite more around-the-clock, on-demand connection than ever. Then there are the opportunity costs of a phone-based childhood that Haidt documents: less (and worse) sleep, less reading, less in-person socializing, less time outside, and less independence. 

All of this is concerning, but I’m especially worried about the impact on critical thinking and concentrating. Our attention spans are like muscles, and the non-stop interruptions and addictive nature of social media make it incredibly difficult for them to develop. Without the ability to focus intensely and follow an idea wherever it leads, the world could miss out on breakthroughs that come from putting your mind to something and keeping it there, even when the dopamine hit of a quick distraction is one click away. 

Another alarming finding in the book is the significant gender divide at play here. Severe mental health challenges seem to have hit young women especially hard in recent years. Meanwhile, young men’s academic performance is worsening, their college attendance is dropping, and they’re failing to develop the social skills and resilience that come from real-world interaction and risk-taking. In other words: Girls are falling into despair while boys are falling behind.  

The solutions Haidt proposes aren’t simple, but I think they’re needed. He makes a strong case for better age verification on social media platforms and delaying smartphone access until kids are older. Literally and figuratively, he argues, we also need to rebuild the infrastructure of childhood itself—from creating more engaging playgrounds that encourage reasonable risk-taking, to establishing phone-free zones in schools, to helping young people rediscover the joy of in-person interaction. Achieving this won’t come from individual families making better choices; it requires coordination between parents, schools, tech companies, and policymakers. It also demands more research into the effects of these technologies, and the political will to act on what we learn.

The Anxious Generation is a must-read for anyone raising, working with, or teaching young people today. With this book, Haidt has given the world a wake-up call about where we’re headed—and a roadmap for how we can change course.  

When I was younger, I would have been perfectly happy spending hours alone in my room reading, learning about my latest obsession, and letting my mind wander. But my mom was intentional about creating opportunities for me to engage and socialize—encouraging me to interact with all the guests who visited our house and making me serve as a greeter at my dad’s work events. She believed that connecting with others was a skill that had to be cultivated, even (or perhaps especially) for an introverted kid like me.

I’ve been thinking about that a lot lately after reading David Brooks's newest book, How to Know a Person: The Art of Seeing Others Deeply and Being Deeply Seen. It was recommended to me by my friend Bernie Noe, and I was eager to dive in because I know David and enjoyed his previous book, The Road to Character. (Also: Whenever Bernie recommends a book to me, I read it.) The key premise is one I haven't found in any other book: that conversational and social skills aren't just innate traits—they can be learned and improved upon.

As someone who has always been more comfortable making software than small talk, I found this idea both refreshing and informative. As a result, even though some of its advice may seem fairly rudimentary, the book is now my favorite of anything David has written.

While reading How to Know a Person, I took a ton of notes and reflected on my own communication style. In Chapter 6, "Good Talks," David dives into what makes a conversation meaningful. It really got me thinking about when I am fully present and engaged in a conversation, and when am I just trying to preserve my energy or avoid being interrupted. I had to laugh at myself a bit, because I know I've been guilty of talking about topics I find fascinating, like the history of fertilizer, without always checking to see if the other person is interested.

One powerful takeaway from the book is the importance of active listening—or, as David calls it, loud listening. “When another person is talking,” he writes, “you want to be listening so actively that you’re practically burning calories.” I’m pretty good at that kind of listening when I’m super interested in a topic, especially when I’m learning something new. But the book made clear how transformative it can be to bring that same enthusiasm when listening to someone talk about a hardship they’re dealing with or an accomplishment they’re proud of.

Fortunately, the book is full of practical advice for doing that. David emphasizes something I’ve found really helpful in my own life: asking open-ended questions—with phrases like "How did you…," "What's it like…," "Tell me about…," and "In what ways…"—that invite people to share their experiences and perspectives in a more in-depth way. David also recommends using the "looping" technique, where you paraphrase what someone has just said to ensure you've understood them correctly. And he endorses what experts call the SLANT method to convey attention and interest in a conversation: Sit up, Lean forward, Ask questions, Nod, and Track the speaker.

What I found especially compelling about the book is how it shows that these skills are relevant across all kinds of relationships and interactions. Whether you're catching up with a close friend, chatting with a coworker, or just exchanging pleasantries with someone while waiting in line for a cheeseburger, being fully present and attuned can transform the encounter. These simple practices can go a long way in making others feel heard and valued.

The more I read, the more I realized how much the book's insights connect to the broader challenges we face in today's world. Back in 1995, when I wrote The Road Ahead, I predicted that technology would make it easier for us to stay connected with our hometowns and share our lives with others. And in many ways, it has. But David argues in Chapter 8, "The Epidemic of Blindness," that technology has also contributed to a growing sense of loneliness and disconnection. We may be more connected than ever, but are we truly seeing and understanding each other?

This question becomes even more urgent when considering the social and political divisions David highlights. The statistics he cites about the rise in depression, suicide, and distrust are alarming, and he makes the case that this social unraveling is fueling our political divides. His discussion about how politics can become a substitute for genuine connection—leading people to get their satisfaction from yelling at those they disagree with instead of trying to understand them—highlights a trend that worries me a great deal.

In the book, David connects these social ills to changes in our education system. He argues that schools have shifted away from teaching what he calls “moral and social skills,” and that this has left us ill-equipped to build strong relationships and communities. It’s an interesting and timely argument for sure, but I wished it were further built out. I’d be interested in reading more about how David defines this type of teaching, how he measures the changes, and how he thinks education can help reverse some of these troubling social trends. In fact, I think there’s another book waiting to be written here.

For the most part, though, what makes David's book so compelling is that it challenges us to put its insights into practice. It's about being intentional in our interactions, whether that means asking more thoughtful questions, fully listening to the answers, or expressing genuine appreciation. It's about approaching conversations with generosity and curiosity, looking for ways to connect and understand. And it's about realizing that even small things—like asking the right question at the right time or giving a nice compliment—can make a big difference in building relationships. I’m certain that what I learned from the book will stay with me for a long time.

Overall, I can’t recommend How to Know a Person highly enough. More than a guide to better conversations, it’s a blueprint for a more connected and humane way of living. It's a must-read for anyone looking to deepen their relationships and broaden their perspectives—and I believe it has the power to make us better friends, colleagues, and citizens.

If you don’t know Chris Anderson’s name, you probably know his work. As the curator of TED for over two decades, Chris has transformed the once-exclusive conference into a global platform for ideas that “change everything”—making TED Talks a household name in the process. Chris and I share a deep interest in how innovation can help tackle major challenges and improve the world. We've collaborated several times, and he’s invited me to the TED stage periodically since 2009. 

So when Chris told me about his new book, Infectious Generosity—which explores how the internet can amplify the impact of generosity—I was excited to dive in.

Chris’s central argument is that communications technology creates both an opportunity and a responsibility to give more. When we can witness the hardships of others firsthand, even from the other side of the planet, our instinct to help is activated. And the internet makes it easy to act on that instinct.

The book is filled with powerful examples of this dynamic in action, including viral fundraising campaigns like the ALS Ice Bucket Challenge, which raised over $200 million to fight the disease (and which I participated in), and online platforms like DonorsChoose, which allows anyone to support a classroom project with just a few clicks. Each story shows the power of people joining up to do extraordinary things.

But Chris doesn't gloss over the challenges of the digital age. Like other observers, he notes that social media platforms have turned the internet into an “outrage-generating machine” that drives us apart instead of bringing us together. As we saw with the spread of Covid-19 misinformation, online spaces can easily promote polarization and falsehoods instead of empathy and truth. What’s more—even as the ease of giving has increased, overall giving levels have not. In fact, a 2022 report from Giving USA found that individual giving as a percentage of disposable income has remained relatively flat over the past four decades.

People are more connected than ever—but that connection hasn’t always fostered the generosity we’d want and expect. That will only happen at scale, Chris argues, if individuals, nonprofits, businesses, and policymakers all make a concerted effort. Fortunately, the book offers a roadmap we can follow: Tell more uplifting stories of everyday generosity, redesign social media to promote prosocial behavior, and expand our definition of generosity itself—to include bridging divides, sharing knowledge, enabling connections, extending hospitality, and others.

I was especially intrigued by Chris's proposal of a “universal giving pledge,” where everyone commits to donating 10 percent of their income or 2.5 percent of their wealth annually. It’s similar to what many religions already encourage of their followers, if only by another name. And it’s reminiscent of the Giving Pledge, which Melinda, Warren Buffett, and I launched in 2010 to encourage billionaires to dedicate the majority of their wealth to philanthropy, either in their lifetime or wills. For me, that has meant working to save and improve lives through the Gates Foundation—which is the most meaningful work of my life.

Just as the Giving Pledge aims to make giving the norm among the wealthy, a universal pledge has the potential to inspire millions of people at all income levels to give more. If universally adopted, Chris calculates, such a pledge would generate over $10 trillion every year and unlock immense new resources to address health, poverty, education, and more.

Reading this book, I was reminded of my own mindset when I first thought about the digital revolution—about how it could bring the world closer together, make people feel less lonely, and help us tackle our biggest challenges. It’s great to see that someone still passionately believes in that promise and has ideas for how we can make good on it.

It's true that a few of Chris’s boldest, most ambitious proposals, like the universal giving pledge, will be challenging to implement. Still, I find his idealism infectious and inspired—especially because advances in artificial intelligence will likely amplify technology's potential as a generosity engine. At a minimum, AI will give us more potent tools to understand causes, mobilize donors, and target giving for maximum impact in the coming years. The key is to design these systems so they identify inequities, catch our biases, tap into the best of human nature, and nudge us toward our most generous selves.

If you want to help create a more generous world but don’t know where to start, Infectious Generosity is the book for you. It's an invitation to rethink and reinvent philanthropy for the digital age—and I believe that if enough of us embraced its message, the world really would be a much more generous place.

There is one writer whose books I’ve reviewed on Gates Notes more than anyone else: Vaclav Smil. I’ve read all of his 44 books, which cover everything from the role of energy in human life to changes in the Japanese diet. I find his perspective to be super valuable. Although sometimes he’s too pessimistic about the upside of new technologies, he’s almost always right—and informative—when it comes to the complexities of deploying those technologies in the real world.

In his newest book, Invention and Innovation: A Brief History of Hype and Failure, Smil looks skeptically at the notion that we’re living in an unrivaled era of innovation. Based on his analysis of fields including agriculture, transportation, and pharmaceuticals, he concludes that our current era is not nearly as innovative as we think. In fact, he says, it shows “unmistakable signs of technical stagnation and slowing advances.”

This conclusion feels especially counterintuitive at a time when artificial intelligence and deep learning are advancing so fast. But to Smil, AI researchers only have managed “to deploy some fairly rudimentary analytical techniques to uncover patterns and pathways that are not so readily discernible by our senses” and produced “impressive achievements on some relatively easy tasks.”

Smil believes there was only one real period of explosive innovation in the past 150 years: 1867-1914. During those years, inventors created internal combustion engines, electric lights, the telephone, inexpensive methods of producing steel, aluminum smelting, plastics, and the first electronic devices. Humanity also gained revolutionary insights in the fields of infectious disease, medicine, agriculture, and nutrition. 

Smil argues that the ensuing years have been lackluster, with far more “breakthroughs that are not” than important inventions that achieve scale and stick in the marketplace. One of his iconic examples of a false breakthrough is leaded gasoline, which helped internal combustion engines operate much more smoothly but produced devastating cognitive declines and millions of premature deaths.

One thing that I agree with him about is how the exponential growth in computing power over the past several decades has given people a false idea about growth and innovation in other areas. Smil acknowledges “the much-admired post-1970 ascent of electronic architecture and performance,” but he concludes that this growth “has no counterpart in … other aspects of our lives.” It’s misguided to assume that anything else will grow as fast as computing power has.

On the other hand, I think Smil underestimates accomplishments in AI. The past two years of AI improvement, particularly large language models, have surprised all of us. In fact, we’re starting to see early signs that machines can produce human-like reasoning—moving beyond just producing answers to questions they were programmed to solve. AI is going to become smart, not just fast. When it achieves what researchers call “artificial general intelligence,” that will give humanity incredible new tools for problem solving in almost every domain, from curing disease to personalizing education to developing new sources of clean energy. And as I wrote earlier this year, we will have to develop strict guidelines and protocols to curtail negative outcomes.

Smil also neglects to account for the convergence of new technologies. In the work I do with the Gates Foundation and Breakthrough Energy, I have a great vantage point for observing innovation driven not just by advances in one area (AI, for example) but by the compounding effects of many different technologies advancing at the same time, like digital simulations, storage capacity, mobile communications, and domain-specific tools such as gene sequencing.

Smil is also pessimistic about many green technologies, including some approaches that I’m investing in. For example, he describes sodium-cooled nuclear fission reactors as pie in the sky. And yet in May I walked on the ground that will soon be broken for just such a reactor. Thanks to advances in digital simulation as well as ample risk capital, TerraPower has designed a sodium-cooled reactor that could be delivering power to the grid by 2030. Even if it takes longer to get running, I’m optimistic that sodium-cooled reactors are not just technically possible but will also prove to be economically viable, safe, and helpful for achieving net-zero carbon emissions.

Every Smil book that I own is marked up with lots of notes that I take while reading. Invention and Innovation is no exception. Even when I disagree with him, I learn a lot from him. Smil is not the sunniest person I know, but he always strengthens my thinking.

When Roger Federer announced his retirement, I thought of a fascinating insight he once gave me into his playing style. One of the keys to his success, he told me, is his incredible ability to keep his cool and remain calm.

Anyone who saw Roger play knows what he meant. When he got down, he knew he might need to push himself a little more, but he never worried too much or got too down on himself. And when he won a point, he didn’t waste a lot of energy congratulating himself. His style was the opposite of someone like John McEnroe, who showed all of his emotions and then some.

I was glad to hear Roger talk about that element of his game, because it’s something I’ve been trying to incorporate in my own way since the mid-70s, when I first came across Timothy Gallwey’s groundbreaking book The Inner Game of Tennis. It’s the best book on tennis that I have ever read, and its profound advice applies to many other parts of life. I still give it to friends today.

Inner Game was published in 1974 and was a big hit. Gallwey, a successful tennis coach based in southern California, introduced the idea that tennis is composed of two distinct games. There’s the outer game, which is the mechanical part—how you hold the racket, how you keep your arm level on your backhand, and so on. It’s the part that most coaches and players tend to focus on.

Gallwey acknowledged the importance of the outer game, but what he was really interested in, and what he thought was missing from most people’s approach, was the inner game. “This is the game that takes place in the mind of the player,” he wrote. Unlike the outer game, where your opponent is the person on the other side of the net, the inner game “is played against such obstacles as lapses in concentration, nervousness, self-doubt, and self-condemnation. In short, it is played to overcome all habits of mind which inhibit excellence in performance.”

That idea resonated with me so well that I read the book several times, which is unusual for me. Before I read it, in just about every match I would say to myself at some point: "I’m so mad that I missed that shot. I’m so bad at this." That negative reinforcement would linger, so during the next point, I was still thinking about that bad shot. Gallwey presented ways of letting go of those negative feelings and getting out of your own way so you could move on to the next point.

Gallwey had one particular insight that seems crazy the first time you hear it. “The secret to winning any game,” he wrote, “lies in not trying too hard.”

How could you expect to win by not trying too hard? “When a tennis player is ‘in the zone,’ he’s not thinking about how, when, or even where to hit the ball,” Gallwey wrote. “He’s not trying to hit the ball, and after the shot he doesn’t think about how badly or how well he made contact. The ball seems to get hit through a process which doesn’t require thought.” (Gallwey was writing at a time when it was still common to use the word “he” to refer to everyone.)

The inner game is really about your state of mind. Is it helping you or hurting you? For most of us, it’s too easy to slip into self-criticism, which then inhibits our performance even more. We need to learn from our mistakes without obsessing over them.

Gallwey and his readers quickly realized that the inner game wasn’t just about tennis. He went on to publish similar books about golf, skiing, music, and even the workplace: He created a consulting business that caters to Fortune 500 companies.

Even though I stopped playing tennis in my 20s so I could focus on Microsoft and didn’t start again until my forties, Gallwey’s insights subtly affected how I showed up at work. For example, although I’m a big believer in being critical of myself and objective about my own performance, I try to do it the Gallwey way: in a constructive fashion that hopefully improves my performance.

And although I’m not always perfect at it, I try to manage teams the same way. For example, years ago, there was an incident where a team at Microsoft discovered a bug in a piece of software they had already shipped to stores. (This was back when software was sold on discs.) They would have to recall the software, at significant cost to the company. When they told me the bad news, they were really beating themselves up. I told them, “I’m glad you’re admitting that you need to replace the discs. Today you lost a lot of money. Tomorrow, come in and try to do better. And let’s figure out what allowed that bug to make it into the product so it doesn’t happen again.”

Tennis has evolved over the years. The best players in the world today play a very different style from the champions of 50 years ago. But The Inner Game of Tennis is just as relevant today as it was in 1974. Even as the outer game has changed, the inner game has remained the same.

When I meet someone who plays bridge, I feel an immediate affinity for them. It's not because I really know anything about them beyond their taste in card games. For all I know, we could be like oil and water once we actually start talking. But we both love bridge, and that makes me more likely to connect with someone.

There are few forces stronger than the power of group identity. The groups we self-identify as are a key part of who we are. Most of the time, these identities aren’t inherently positive or negative—but each one of them shapes the way we see the world.

In his terrific book Why We’re Polarized, Ezra Klein argues that identity is the answer to the question suggested by his title. The phrase “identity politics” has been thrown around a lot in recent years—usually in a negative context—but Klein explains that it’s human instinct to let our group identities guide our decision making. “A group can know more and reason better than an individual,” he says, “and thus human beings with the social and intellectual skills to pool knowledge had a survival advantage over those who didn’t.”

Why We’re Polarized is fundamentally a book about American politics, but I thought it was also a fascinating look at human psychology. One of my main takeaways was that many of us might need to reframe how we think about changing someone’s mind. I’m a data person (another identity I have!), so my instinct is always to use numbers and logic to convince people of something. When I meet someone who disagrees with me, I tend to explain the merits of my position and compare results of the two different approaches.

But Why We’re Polarized makes it clear that group identity can overrule any argument for or against an issue. If you want to bridge the gap, it’s more productive to appeal to someone’s identity than to their logic.

This is especially true for political issues. Klein explains how political identity used to be more rooted in where you lived rather than what party you belonged to. (This wasn’t always a good thing: He devotes an entire chapter to the damaging influence of the Dixiecrats.) The parties themselves were seen more as shortcuts you could use to inform your choices. “We may not know the precise right level of taxes… but we know whether we support the Democratic, Republican, Green, or Libertarian party,” Klein says.

Americans tended to vote for candidates who made the most sense for where they lived rather than whether they were a Democrat or Republican, which led to a lot more ticket splitting. Between 1972 and 1980, 46 percent of voters in contested districts voted for a different party House candidate from who they supported for president. By 2018, only 3 percent of voters did.

What changed? The political parties themselves. For a lot of different reasons—starting with the fight for the Civil Rights Act of 1964 and including the rise of cable news—both parties have to varying degrees adopted more extreme positions over the last several decades. As a result, the party identities themselves have become more polarized and caused people to dig in more firmly.

I was especially interested to read what Klein had to say about the relationship between social media and polarization. The internet gets a lot of criticism for how it has divided us, but people were seeking out media that corresponded to their political affiliation well before social media. At the same time, it is undeniable, that its ability to connect the fringes of the parties together has exacerbated the situation. When you look at something like January 6^th, it’s clear that the internet played a role in enabling the most extreme people to find each other and organize.

Overall, though, Klein thinks that our polarization problem goes much deeper than just social media. He’s quite persuasive, and I agree with him. Like most books, he is much better about diagnosing the problem and educating us on the historical context than he is at offering solutions. Klein has a couple ideas about improvements we could make—such as restructuring the Supreme Court or changing the Electoral College—but he acknowledges none of them are a true solution.

At the end of last year, I said that one of my plans for 2022 was to read more about polarization. It’s a problem I’m quite concerned about, and this helped me understand the phenomena much better. I wouldn’t say I finished the book more optimistic about our ability to tackle the problem, which is even more daunting than I thought. But if you want to understand what’s going on with politics in the United States, this is the book to pick up.

Vaclav Smil is my favorite author, but I sometimes hesitate to recommend his books to other people. His writing, while brilliant, is often too detailed or obscure for a general audience. (Deep dives on Japanese dining habits or natural gas can be a tough sell for even the smartest, most thoughtful readers.) Still, I’m a big enough fan to keep telling my friends and colleagues about his books, even though I know most of them won’t take me up on my recommendations.

That’s why I was thrilled when Vaclav released his most accessible book yet. Numbers Don’t Lie: 71 Things You Need to Know About the World, which came out last fall, takes everything that makes his writing great and boils it down into an easy-to-read format. I unabashedly recommend this book to anyone who loves learning.

This is probably the most information Vaclav has ever put in a book, and yet it’s by far the most digestible. Each chapter is just a couple pages long and covers one of the 71 facts mentioned in the title. Here are three that I found particularly interesting:

1.

You can thank sweat glands for our big brains.

Humans are the grand champions of sweating. We’re able to remove heat from our bodies through perspiration better than any other mammal (partly because we have very little hair). Vaclav writes, “In the race of life, we humans are neither the fastest nor the more efficient. But thanks to our sweating capabilities, we are certainly the most persistent.”

Our ancestors had better endurance than the animals they hunted for food, which allowed them to run down rich sources of protein that provided the fuel for our brains to develop. The next time you feel miserable on a hot day, just think about how all the sweating you’re doing is the reason you’re so smart!

2.

The French are drinking a lot less wine than they used to.

“Viticulture, wine-drinking, and wine exports have been long established as one of the key signifiers of national identity” in France, writes Vaclav. In 1926, the average French person drank an impressive 136 liters of wine (or more than 35 gallons). But by 2020, that figure had shrunk to just 40 liters.

The idea that French wine consumption is now a third of what it was a century ago is amazing to me because of what it might reveal about how society is changing. While young French people are drinking less alcohol overall, the consumption of mineral and spring water has doubled since 1990. Does that mean the French are becoming more health conscious? Was life just so bleak in the 1920s that people had to drink? Have people replaced drinking wine with other diversions like watching TV or browsing the web? I love how this book forces you to think about the story behind a seemingly niche statistic.

3.

The 1880s might be the most consequential decade in human history.

One of my favorite things about Vaclav’s writing is his ability to put history in context. Although it’s tempting to see the era we’re living in now as a time of unprecedented innovation, he argues that the 1880s saw the real technology boom. The decade saw the discovery of electricity and the internal combustion engine—along with somewhat less consequential but still important innovations like the ballpoint pen, the modern bicycle, and Coca-Cola. If you want to read more about the inventions the 1880s gave us, you can download a free chapter here:

Vaclav believes that progress comes in fits and starts rather than in a constant stream. Humanity will go through long periods where everything stays the same, and then a new invention will come along that sets off a rapid period of change. For example, Thomas Edison’s discovery enabled the creation of the electric elevator in 1889. This, in turn, let us build taller buildings like skyscrapers since people would no longer have to rely on stairs to reach the top floor. City skylines would look a lot different today if it weren’t for the 1880s.

If you read Numbers Don’t Lie and like it, you might also enjoy Vaclav’s latest book Grand Transitions. Numbers Don’t Lie(He is nothing if not prolific, having released two books during the pandemic.) It looks at how societies are shaped by shifts in demographics, agriculture, economics, and energy use. It’s not quite as accessible as , but the subject matter is so interesting that I think people will find it worthwhile.

Vaclav finds as much joy and fascination in looking to the past as anyone else I know. As someone who tends to be optimistic about technology—maybe even too optimistic at times—I appreciate how his natural skepticism about future innovation keeps my outlook realistic. If you’re looking for someone to help you understand how history ties together, you can’t do better than Vaclav—and Numbers Don’t Lie is a great place to start.

GE is a mythic corporation. It was at one time the largest, most powerful company in the world. Its founding story includes the innovator Thomas Edison and financier J.P. Morgan. Its legendary CEO Jack Welch, who wrote five bestselling books on leadership, became a model for an entire generation of executives. When GE started using Microsoft software in our early days, that gave us a huge boost in the market, because GE was such a bellwether company.

It turns out that the word “mythic” is the perfect word for GE. The corporation has come crashing to Earth in one of the greatest downfalls in business history. Its workforce has been hollowed out, from 333,000 employees in 2017 to fewer than 174,000 at the end of last year. Its share price has fallen precipitously. In 2018, GE was dropped from the Dow Jones Industrial Average after more than a century in the index.

GE’s fall is not the result of innovators developing a better jet engine or wind turbine. It’s also not a case of outright fraud, like Enron. It’s a textbook case of mismanagement of an overly complex business.

Only a few people saw it coming (including one, ironically, from J.P. Morgan’s namesake bank). I wish I could tell you that I was one of them, but I was just as surprised as most people.

That’s why I was eager to read Lights Out: Pride, Delusion, and the Fall of General Electric, by the Wall Street Journal reporters Thomas Gryta and Ted Mann. I wanted to understand what really went wrong and what lessons this story holds for investors, regulators, business leaders, and business students.

At times, it was a bit hard for me, as a former CEO, to read such harsh criticism of fellow leaders, including people I know and like. But I got a lot out of reading this book. Gryta and Mann gave me the detailed insight I was looking for into the culture, decisions, and accounting that eventually caught up to GE in a gigantic way.

My first big takeaway is that one of GE’s greatest apparent strengths was actually one of its greatest weaknesses. For many years, investors loved GE’s stock because the GE management team always “made their numbers”—that is, the company produced earnings per share at least as large as what Wall Street analysts predicted. It turns out that culture of making the numbers at all costs gave rise to “success theater” and “chasing earnings.” In Gryta and Mann’s words, “Problems [were] hidden for the sake of preserving performance, thus allowing small problems to become big problems before they were detected.”

Chapter 14 of Lights Out details many of the gimmicks GE employed to make the numbers look better than they really were. For example, Gryta and Mann report that GE would sometimes artificially boost quarterly profits by selling an asset (e.g., a diesel train) to a friendly bank, knowing that it could then buy back the asset at a time of GE’s choosing.

There are a lot of ways a company can end up with a culture that rewards gaming the numbers. Although Steve Ballmer and I made our share of strategic mistakes, we were maniacal about making sure our numbers were rock solid and avoiding incentive systems where people could cram a lot of sales into a quarter in order to look good or meet some quota. Satya Nadella works the same way today.

In many companies, bad news travels very slowly, while good news travels fast. We tried hard to combat that. A team member might send me mail saying “we just won a software design competition,” and “isn’t this amazing?” I’d typically respond, “Why am I hearing about this one? That’s not statistically representative. How many competitions did we lose?” I used the term “making bad news travel fast” all the time. I wanted to catch negative trends early, when we could still do something about them.

My second big takeaway from Lights Out is that GE didn’t have the right talent and systems to bundle together a dizzying array of unrelated businesses—including moviemaking, insurance, plastics, and nuclear power plants—and manage them well. Investors bought into the notion that the company’s world-renowned training made it better at managing things than anyone else, and that GE could produce consistent profits even in highly cyclical markets. And GE successfully persuaded people that its generalists could avoid the pitfalls that had tripped up big conglomerates in the past.

In reality, those generalists often didn’t understand the specifics of the industries they had to manage and couldn’t navigate trends in their industries. For example, the authors make the case that CEO Jeff Immelt didn’t have a good handle on its huge banking unit, GE Capital. “Making money from [GE Capital] seemed shockingly simple to him at first, as it had to Welch, but the balance sheets were treacherously complex, and deep risks lurked there and were not always easily spotted in the quarterly profits and losses,” write Gryta and Mann. One former GE executive told the authors that “Immelt struggled with basic concepts—the difference between secured and unsecured debt, for instance, which was fundamental to a lending operation like GE Capital.”

This dynamic was not confined to Immelt. It was rampant throughout the company’s top ranks. As a result, the ability of top executives to understand what was really going on was quite limited. The only people who could actually dig down into the numbers and see what was going on were in finance. And as I mentioned above, the finance people didn’t have much incentive to bring negative news to Welch or Immelt.

In my role at our foundation, I sometimes hear fellow philanthropists say things like, “I just wish my grantees could operate more like a business.” The story of GE, led by very smart men who cared deeply about their work, should tamp down that kind of talk. The truth is that businesses, even the giants of industry, are just as susceptible to mistakes as any nonprofit. Anyone who wants to avoid the mistakes made by GE should read this book.

Just before COVID-19 hit, I was paired with Roger Federer in a tournament to benefit children’s education in Africa. When I watch Roger play, I’m in awe. As the late novelist David Foster Wallace wrote, he is “one of those rare, preternatural athletes who appear to be exempt, at least in part, from certain physical laws.”

Here’s the surprising part about Roger’s greatness: As a young kid, he didn’t focus on tennis and didn’t get fancy coaching or strength training. He played a wide range of different sports, including skateboarding, swimming, ping pong, soccer, and badminton. He didn’t start playing competitive tennis until he was a teenager. Even then, his parents discouraged him from taking it too seriously.

I learned this from reading a good, myth-debunking book called Range: Why Generalists Triumph in a Specialized World. The sports journalist David Epstein uses Roger’s experience as his opening example of the underappreciated benefits of delaying specialization and accumulating a breadth of different experiences. “In a world that increasingly incentivizes, even demands, hyperspecialization,” he writes, “we … need more Rogers: people who start broad and embrace diverse experiences and perspectives while they progress.”

Epstein, whom I learned about from his fantastic 2014 TED talk on sports performance, acknowledges that there are certain pursuits, like golf and classical music, where it does make sense to go all in as early as possible. But these are outliers, because they’re rooted in repetitive patterns and clearly defined solutions. “The world is not golf, and most of it isn’t even tennis,” Epstein writes. Instead, the world is like a game where “you can see the players on the court with balls and rackets, but nobody has shared the rules. It is up to you to derive them, and they are subject to change without notice.”

My own career fits the generalist model pretty well. As a kid, I used to sneak out of my basement bedroom to do late-night coding at the University of Washington, but my passion for computers was always mixed with many other interests. I spent a lot of time reading books on a wide range of topics.

I believe that one of the key reasons Microsoft took off is because we thought more broadly than other startups of that era. We hired not just brilliant coders but people who had real breadth within their field and across domains. I discovered that these team members were the most curious and had the deepest mental models.

Epstein provides a good framework for understanding why polymaths are so important for innovation. “In kind environments, where the goal is to re-create prior performance with as little deviation as possible, teams of specialists work superbly.” That’s why if I had to get surgery, I’d seek out a subspecialist who had a lot of experience with whatever procedure I needed. But when it’s a “wicked environment,” your job is not to repeat a complex procedure. By definition, it’s to do something that no one has done before. Epstein reports that when researchers study great innovators, they find “systems thinkers” with an “ability to connect disparate pieces of information from many different sources” and who “read more (and more broadly) than other technologists.” Theatrical innovator Lin-Manuel Miranda calls this having “a lot of apps open” in one’s brain at the same time. I like that image.

Epstein finds that there’s another good reason to encourage range: “In a wicked world, relying upon expertise from a single domain … can be disastrous.” Chapter 10 (“Fooled by Expertise”) is dedicated to showing how hyperspecialists are susceptible to tunnel vision. For example, he cites a study of 284 top experts on Soviet and Russian affairs. This 20-year study found that, on average, the so-called experts “were bad at short-term forecasting, bad at long-term forecasting, and bad at forecasting in every domain…. [They were] roughly as accurate as a dart-throwing chimpanzee.” But there was one subgroup that turned out to be much more accurate. These were experts “who were not vested in a single approach,” “chose to look at new evidence, whether or not it agreed with their current beliefs,” and “were much more likely to adjust their ideas … when an outcome took them by surprise.”

Epstein offers up Charles Darwin as the ultimate example of someone whose breadth made it possible for him to remain open-minded and innovative. Before Darwin got aboard the HMS Beagle and sailed to the Galapagos, he had trained not only in natural history but also medicine, theology, philosophy, and geology. This cross-training helped him build the intellectual muscles he would need to overturn centuries of dogma. “He made a point of copying into his notes any fact or observation he encountered that ran contrary to a theory he was working on,” Epstein writes. “He relentlessly attacked his own ideas, dispensing with one model after another, until he arrived at a theory that fit the totality of the evidence.”

My only criticism of Range is that you could come away with the impression that Epstein, a generalist himself, is too critical of specialists. If you’re enthusiastic about a hyperspecialized field like molecular biology or quantum physics, go for it. Just give yourself some room to explore what your friends and colleagues in other fields are learning.

My last holiday books list included a novel called An American Marriage which really stuck with me over the previous year. I was deeply touched by its story of a husband torn away from his wife by a false accusation that lands him in prison. The book did a beautiful job of showing how incarceration can devastate a family, even after release from prison.

As moving as the book was, the story was fiction. But the idea of a family torn apart by mass incarceration is not. If you’re interested in learning more about the real lives caught up in our country's justice system, I highly recommend The New Jim Crow by Michelle Alexander. It offers an eye-opening look into how the criminal justice system unfairly targets communities of color—and especially Black communities.

The book was released more than 10 years ago, but this is a topic that has taken on extra relevance this year. The horrifying killings of George Floyd and Breonna Taylor set off a summer of protests that put Black Lives Matter front and center. Like many white people, I’ve committed to reading more about and deepening my understanding of systemic racism. Alexander’s book is about much more than the police—whom she describes as the “point of entry” into the justice system—but it provides useful context to understand how we got to where we are.

Alexander explains how mass incarceration is a cycle. Once you’ve been in prison, you can’t often get a job after you get out because having a felony on your record makes it hard to get hired. In some cases, the only way to make money and support your family is through illicit means—which can land you back in prison. The result of this cycle is a permanent underclass that is disproportionately Black and low-income. (Alexander also talks about this in Ava DuVernay’s excellent documentary 13^th.)

The book is good at explaining the history and the numbers behind mass incarceration. I was familiar with some of the data, but Alexander really helps put the numbers—especially around sentencing and the War on Drugs—in context. The New Jim Crow was published a decade ago, so some of the figures are outdated. The incarceration rates have only gone down a tiny bit in the last ten years, though, and the general picture she paints is still highly relevant.

Alexander argues that the criminal justice system has been the primary driver of racial inequity in America since the end of the Jim Crow era (hence the book’s title). The U.S. is unique in putting so many people in jail for such long periods. We lock people up at five to ten times the rate of other industrialized countries according to the Sentencing Project, and prison spending has risen three times faster than education spending over the last three decades.

I was particularly shocked to read the stories Alexander uses to illustrate the extreme sentences that many judges are forced to hand down. Because of how sentencing laws are often structured, judges sometimes don’t have “judicial discretion”—the ability to make decisions based on their personal evaluation of the defendant. Their hands are tied, especially in drug cases. Alexander tells the story of one federal judge who broke down in tears when he was forced to sentence a man to “ten years in prison without parole for what appeared to be a minor mistake in judgment in having given a ride to a drug dealer for a meeting with an undercover agent.”

It’s clear that we need a more just approach to sentencing and more investment in Black communities and other communities of color. The good news is that support for change is growing. Although there has only been modest progress on this front since The New Jim Crow was published in 2010, a new bipartisan coalition has emerged in support of prison reform in that time. (I met with a bipartisan group to learn about the subject during a trip to Georgia in 2017.) And I am hopeful that this year’s protests for Black lives—which are now considered the largest movement in U.S. history—will go a long way toward building more public support for updating our justice system.

I hope Alexander plans on writing a follow-up to The New Jim Crow someday. The latest edition includes a new preface that touches on the Black Lives Matter movement, but it was published before the events of this summer. She’s so good at explaining the historical context behind the injustices that Black people experience every day, and I am eager to hear her thoughts on how this year might have moved us closer to a more equal society.

A couple years ago, Melinda and I visited a state prison in Georgia as part of our foundation’s work on U.S. poverty. I’d never been to a prison before, and it was an eye-opening experience.

The most memorable part was the discussion we had with some of the inmates about transitioning back into society. Although most were looking forward to leaving prison behind, some were clearly anxious about it. One man told us he was scared to re-enter society after so many years behind bars. Another mentioned that it felt like he was a car about to be dropped into the middle of a racetrack where the other cars are already going 200 miles per hour.

I couldn’t help but think about that conversation when I was reading An American Marriage by Tayari Jones. Although it’s fictional, the story is about the question at the heart of the anxiety Melinda and I saw that day: how do you rebuild your life after prison?

Our daughter Jenn recommended that we read this deeply moving story about how one incident of injustice reshapes the lives of a black couple in the South and eventually dooms their relationship. Roy and Celestial are newlyweds living in Atlanta. They seemed to have it all: good careers, a decent house, and a lot of love for one another (although their marriage wasn’t perfect).

That all changes when Roy gets falsely accused of rape and sentenced to 12 years in prison. Despite how radically this event changes their lives, Jones doesn’t spend much time on it. She devotes only five pages to Roy’s arrest and trial. Her message is clear: Roy is innocent, Celestial knows it, and neither fact matters. He’s caught up in the system regardless.

What Jones is more interested in is how incarceration changes relationships. About half of the book is letters exchanged between Roy and Celestial while he’s locked up. Although they start out sweetly, the letters become more tense as time goes on. Eventually, Celestial stops writing to Roy altogether. By the time he gets released from prison seven years early, she’s moved on. (I promise this isn’t a spoiler. It’s in the book’s jacket description!)

There’s this mythical notion that you’ll wait forever for the person you love. Penelope from the Odyssey is the classic example—she fights off potential suitors for 20 years waiting for her husband, Odysseus, to return from war.

It’s a romantic idea, but is it realistic? Jones doesn’t seem to think so. We all like to imagine we’d be Penelope in that situation, but I suspect many would end up like Celestial instead. She writes to Roy, “You may feel like you’re carrying a burden, but I shoulder a load as well.” Later, she says, “A marriage is more than your heart, it’s your life. And we are not sharing ours.”

The fact that their marriage didn’t have a fairytale ending felt realistic. Roy’s unjust incarceration—and the separation it caused—pushed on the seams that already existed in their relationship, and eventually those seams broke. Despite her decision to leave him, Celestial is a sympathetic character. You understand why she made her choice.

An American Marriage is fundamentally a story about how incarceration hurts more than just the person locked up. It’s also a reminder of how draconian our criminal justice system can be—especially for black men like Roy. Once you get sucked into that system, you’re marked for life. Everything you were or had can disappear while you’re in prison.

In a letter to his lawyer, Roy writes about how things have been difficult for Celestial but even more difficult for him. “I try to see her side of things, but it’s hard to weep for anyone who is out in the world living their dream,” he says.

Jones is such a good writer that you can’t help but empathize with Roy and Celestial. Both have been put into a super-difficult position. I obviously haven’t experienced what they go through, but the characters—and their reactions to the situation—ring true to me.

I wouldn’t say An American Marriage is a light, easy read, but it’s so well-written that you’ll find yourself sucked into it despite the heavy subject matter. If you’re looking for something thought-provoking to read this winter, you should add this one to your list.

Why do we love our families?

The sociologist Nicholas Christakis would probably give way more practical answers than I would. He’d argue that our emotional connection gives us a greater incentive to work together to ensure the survival of our bloodlines. If we’re ever attacked, our larger, combined family unit is more likely to successfully defend ourselves. We’re also more likely to share food and supplies with one another, upping our chances of living through a tough winter.

In his terrific book Blueprint, Christakis explains that humans have evolved to work together and be social. Although this instinct originally developed because it made us more likely to live longer, our need to form groups has had a huge impact on human history.

Early in the book, Christakis says, “The human ability to construct societies has become an instinct. It is not just something we can do—it is something we must do.” He believes that this instinct has led to eight common traits that—with very few exceptions—you can find in every society on earth. These eight traits form what he calls the “social suite:

1. Individual identity
2. Love for partners and children
3. Friendship
4. Social networks
5. Cooperation
6. Preference for your own group
7. Some form of hierarchy
8. Social learning and teaching

Most of the book is devoted to explaining how each of these traits is found in seemingly disparate peoples, from the Roman Empire to the Turkana people of Kenya. Our world has gone from being small groups of hunter-gatherers that were closely related to the modern world where you can live in a city with millions of other people. The fact that the social suite has remained constant despite those changes is amazing.

But the social suite alone is only part of the story. If you want to explain human behavior, there’s a lot going on. You’ve got the genetics you were born with. You’ve got hormones running through the body. You’ve got your childhood and how that shaped you. And you’ve got learned behaviors—the understanding of what’s allowed and what’s not allowed that is passed to you through societal norms.

Blueprint focuses mostly on the last part. If you want a more complete picture, I recommend the book Behave by Robert Sapolsky. My older daughter suggested I read it (Sapolsky was one of her favorite professors in college), because it’s a super in-depth look at why humans act the way they do. He’s giving you a framework down to the biological and hormonal level, while Christakis focuses more on person-to-person interactions.

Behave is really long, though—nearly 700 pages!—and the incredible level of detail isn’t for everyone. It almost feels like a very well-written textbook. Blueprint is a lot more accessible for a general audience. I recommend starting with Christakis and then, if your interest in the subject is piqued, moving onto Sapolsky.

One of the things that makes Blueprint so readable is all of the fascinating examples and stories that Christakis uses. The book begins by looking at a bunch of different shipwrecks that resulted in people getting stranded on deserted islands. Each group had to develop their own form of society, and some were more successful than others. The ones that performed the best (“best” meaning that a high percentage of its people survived to be rescued) embodied some or most elements of the social suite. The societies that didn’t have these elements fell apart quickly, with several even devolving into cannibalism.

I was particularly fascinated by one section of the book where Christakis compares chimpanzees and bonobos. Chimps are super aggressive with each other and sometimes will kill members of their own group to assert dominance. Bonobos, on the other hand, are largely peaceful and playful creatures. They’re one of the only species other than humans who engage in sex for pleasure, not just for procreation purposes.

Christakis offers a couple theories for why the two types of apes are so different, even though they look so similar. Chimpanzees were more likely to share territory with gorillas and had less access to food than the bonobos, so aggressive chimps might have had a better chance to survive. Or maybe bonobo females—like humans—evolved to value cooperation over aggression when choosing a mate.

I was a little surprised to learn that the field of comparing the social behaviors of humans with other species isn’t more developed. Christakis appears to be at the frontier of this, and Blueprint only gives you a surface level understanding.

I also wish he had gone deeper on the main conclusion of his book: that every human being on earth has more in common than not. It raises big questions, like how we can leverage that commonality to get things done. Can we really get 7 billion people to work together and solve big problems like climate change? Are our similarities powerful enough to overcome the few differences we do have?

Christakis doesn’t answer these questions, but he does imply that the answer is yes by showing that we have an innate capability and need to cooperate. A lot of people are fascinated by the differences between us—but the differences are actually pretty minor compared to the similarities. In that regard, Blueprint is a fundamentally optimistic book.

I didn’t expect to finish a book about behavior feeling more hopeful, but Christakis surprised me. It’s easy to feel down reading news headlines every day about how polarized we’re becoming. Blueprint is a refreshing reminder that, when people say we’re all in this together, it’s not just a platitude—it’s evolution.

I stopped listening to music and watching TV in my 20s. It sounds extreme, but I did it because I thought they would just distract me from thinking about software. That blackout period lasted only about five years, and these days I’m a huge fan of TV shows like Narcos and listen to a lot of U2, Willie Nelson, and the Beatles.

Back when I was avoiding music and TV in the hope of maintaining my focus, I knew that lots of other people were using meditation to achieve similar ends. But I wasn’t interested. I thought of meditation as a woo-woo thing tied somehow to reincarnation, and I didn’t buy into it.

Lately, though, I’ve gained a much better understanding of meditation. I’m certainly not an expert, but I now meditate two or three times a week, for about 10 minutes each time. Melinda meditates too. Sometimes we sit to meditate together. (We use comfortable chairs; there’s no way I could do the lotus position.)

I now see that meditation is simply exercise for the mind, similar to the way we exercise our muscles when we play sports. For me, it has nothing to do with faith or mysticism. It’s about taking a few minutes out of my day, learning how to pay attention to the thoughts in my head, and gaining a little bit of distance from them.

Andy Puddicombe, the 46-year-old cofounder and voice of the popular Headspace app, was the person who turned me from skeptic to believer. Prior to finding Headspace, I had read several books about meditation, all of which intimidated me. They made me think that the investment in terms of time and energy was just too high. Headspace made the barrier to entry low enough for me. It’s just 10 minutes a day of listening to Andy’s soothing British accent and trying to stay with him. Andy has taken some heat from hard-core meditators for his low-barrier approach, but he got me to take up meditation and stick with it. I’m glad he did.

If you want to try meditation for yourself, one good way to ease into it—especially if you’re as skeptical as I was—is to pick up a copy of Andy’s book, The Headspace Guide to Meditation and Mindfulness. Andy’s a witty storyteller and offers lots of helpful metaphors to explain potentially tricky concepts, which makes the book an easy, enjoyable read. Andy presents the evidence base behind these practices in sections called “What the research shows” so you know the benefits are legitimate. And the book also helps you see that Andy himself is legitimate. He’s an ordained Buddhist monk who trained for many years in monasteries in India, Nepal, Myanmar, Thailand, Australia, Russia, and Scotland.

The book begins with Andy describing one of them: “Locked in, day and night, surrounded by high stone walls and with no way of contacting anyone on the outside, at times it had felt more like a prison.”

At another monastery, the monks served trainees curry and rice every day, and they made the trainees eat it very slowly over the course of exactly an hour. One super hot day, the monks placed in front of each trainee a wonderful surprise: ice cream. “It was like being a child at a birthday party when the cake comes out.” Unfortunately, the trainees soon discovered they were not allowed to touch the ice cream until they had eaten their curry and rice in the painfully slow way they’d been taught. As the ice cream melted in front of him, he felt angry, then sad and guilty for feeling angry—just as the monks knew would happen.

It turns out that monastic life wasn’t right for Andy. As we learn in the book, after ten years he left and—I kid you not—became a circus clown in London. He wanted to be fully engaged in the world rather than cloistering himself away in artificially quiet retreats.

While he was a clown, he started teaching meditation to those with severe anxiety and other conditions. A few years later, he started Headspace to bring meditation to the masses. He felt that meditation was a skill everyone could learn without sitting behind high stone walls or being subjected to mind games.

Melinda and I enjoyed Andy’s work so much that we reached out to him to see whether he might be willing to spend some time teaching our family. He was glad to do it, which was a real treat for us. For a day and a half, Andy helped us and two of our kids through exercises that are similar to the ones you’ll find in the book. Andy was just as warm, humble, and real as we’d imagined from reading his book and listening to him on the app.

I’m not sure how much meditation would have helped me concentrate in my early Microsoft days, because I was monomaniacally focused without it. But now that I’m married, have three children, and have a broader set of professional and personal interests, it’s a great tool for improving my focus. It’s also helped me step back and get some ease with whatever thoughts or emotions are present. I like what I’m getting from my 10 minutes every few days. I’m grateful to Andy for helping me on this journey.

The human mind wants to worry. This is not necessarily a bad thing—after all, if a bear is stalking you, worrying about it may well save your life. Although most of us don’t need to lose too much sleep over bears these days, modern life does present plenty of other reasons for concern: terrorism, climate change, the rise of A.I., encroachments on our privacy, even the apparent decline of international cooperation.

In his fascinating new book 21 Lessons for the 21st Century, the historian Yuval Noah Harari creates a useful framework for confronting these fears. While his previous best sellers, Sapiens and Homo Deus, covered the past and future respectively, his new book is all about the present. The trick for putting an end to our anxieties, he suggests, is not to stop worrying. It’s to know which things to worry about, and how much to worry about them. As he writes in his introduction: “What are today’s greatest challenges and most important changes? What should we pay attention to? What should we teach our kids?”

These are admittedly big questions, and this is a sweeping book. There are chapters on work, war, nationalism, religion, immigration, education, and 15 other weighty matters. But its title is a misnomer. Although you will find a few concrete lessons scattered throughout, Harari mostly resists handy prescriptions. He’s more interested in defining the terms of the discussion and giving you historical and philosophical perspective.

He deploys, for example, a clever thought experiment to underscore how far humans have come in creating a global civilization. Imagine, he says, trying to organize an Olympic Games in 1016. It’s clearly impossible. Asians, Africans and Europeans don’t know that the Americas exist. The Chinese Song Empire doesn’t think any other political entity in the world is even close to being its equal. No one even has a flag to fly or anthem to play at the awards ceremony.

The point is that today’s competition among nations—whether on an athletic field or the trading floor—“actually represents an astonishing global agreement.” And that global agreement makes it easier to cooperate as well as compete. Keep this in mind the next time you start to doubt whether we can solve a global problem like climate change. Our global cooperation may have taken a couple of steps back in the past two years, but before that we took a thousand steps forward.

So why does it seem as if the world is in decline? Largely because we are much less willing to tolerate misfortune and misery. Even though the amount of violence in the world has greatly decreased, we focus on the number of people who die each year in wars because our outrage at injustice has grown. As it should.

Here’s another worry that Harari deals with: In an increasingly complex world, how can any of us have enough information to make educated decisions? It’s tempting to turn to experts, but how do you know they’re not just following the herd? “The problem of groupthink and individual ignorance besets not just ordinary voters and customers,” he writes, “but also presidents and CEOs.” That rang true to me from my experience at both Microsoft and the Gates Foundation. I have to be careful not to fool myself into thinking things are better—or worse—than they actually are.

What does Harari think we should do about all this? He offers some practical advice, including a three-prong strategy for fighting terrorism and a few tips for dealing with fake news. But his big idea boils down to this: Meditate. Of course he isn’t suggesting that the world’s problems will vanish if enough of us start sitting in the lotus position and chanting om. But he does insist that life in the 21st century demands mindfulness—getting to know ourselves better and seeing how we contribute to suffering in our own lives. This is easy to mock, but as someone who’s taking a course on mindfulness and meditation, I found it compelling.

As much as I admire Harari and enjoyed 21 Lessons, I didn’t agree with everything in the book. I was glad to see the chapter on inequality, but I’m skeptical about his prediction that in the 21st century “data will eclipse both land and machinery as the most important asset” separating rich people from everyone else. Land will always be hugely important, especially as the global population nears 10 billion. Meanwhile, data on key human endeavors—how to grow food or produce energy, for example—will become even more widely available. Simply having information won’t offer a competitive edge; knowing what to do with it will.

Similarly, I wanted to see more nuance in Harari’s discussion of data and privacy. He rightly notes that more information is being gathered on individuals than ever before. But he doesn’t distinguish among the types of data being collected—the kind of shoes you like to buy versus which diseases you’re genetically predisposed to—or who is gathering it, or how they’re using it. Your shopping history and your medical history aren’t collected by the same people, protected by the same safeguards, or used for the same purposes. Recognizing this distinction would have made his discussion more enlightening.

I was also dissatisfied with the chapter on community. Harari argues that social media including Facebook have contributed to political polarization by allowing users to cocoon themselves, interacting only with those who share their views. It’s a fair point, but he undersells the benefits of connecting family and friends around the world. He also creates a straw man by asking whether Facebook alone can solve the problem of polarization. On its own, of course it can’t—but that’s not surprising, considering how deep the problem cuts. Governments, civil society, and the private sector all have a role to play, and I wish Harari had said more about them.

But Harari is such a stimulating writer that even when I disagreed, I wanted to keep reading and thinking. All three of his books wrestle with some version of the same question: What will give our lives meaning in the decades and centuries ahead? So far, human history has been driven by a desire to live longer, healthier, happier lives. If science is eventually able to give that dream to most people, and large numbers of people no longer need to work in order to feed and clothe everyone, what reason will we have to get up in the morning?

It’s no criticism to say that Harari hasn’t produced a satisfying answer yet. Neither has anyone else. So I hope he turns more fully to this question in the future. In the meantime, he has teed up a crucial global conversation about how to take on the problems of the 21st century.

This post originally appeared in the New York Times Book Review.

When I was a kid, I read a lot of sci-fi books. One of the most common themes was “man vs. machine,” which often took the form of robots becoming self-aware and threatening humanity. This theme has also become a staple of Hollywood movies like The Terminator and The Matrix.

Despite the prevalence of this theme, I don’t lose any sleep worrying about this scenario. But I do think we should spend more time thinking about the implications—positive and negative—of recent progress in artificial intelligence, machine learning, and machine vision. For example, militaries have begun to develop drones, ships, subs, tanks, munitions, and robotic troops with increasing levels of intelligence and autonomy.

While this use of A.I. holds great promise for reducing civilian casualties and keeping more troops out of harm’s way, it also presents the possibility of unintended consequences if we’re not careful. Earlier this year, U.N. Secretary General António Guterres called global attention to these threats: “The weaponization of artificial intelligence is a growing concern. The prospect of weapons that can select and attack a target on their own raises multiple alarms…. The prospect of machines with the discretion and power to take human life is morally repugnant.”

Unfortunately, my first attempt to educate myself on autonomous weapons was a bust. I read a book that was dry and felt really outdated. Then a few months ago I picked up Army of None: Autonomous Weapons and the Future of War, by Paul Scharre. It’s the book I had been waiting for. I can’t recommend it highly enough.

Scharre is a great thinker who has both on-the-ground experience and a high-level view. He’s a former Army Ranger who served four tours of combat duty in Iraq and Afghanistan. He then went onto a policy role at the U.S. Department of Defense and led the working group that drafted the government’s policy on autonomous weapons. He’s currently a policy expert at the Center for a New American Security, a center-left think tank in DC.

He is also a good writer. Scharre writes clearly about a huge range of topics: computer science, military strategy, history, philosophy, psychology, and ethics. He gives you the right grounding to start participating in the debate over where our country should draw the line on these powerful technologies.

Scharre makes clear from the beginning that he has no problem with some well-bounded military uses of autonomy. For example, he brings you along for a tour of the U.S. Navy’s Aegis Combat System, an advanced system for tracking and guiding missiles at sea. Aegis has a mode of operation in which human operators delegate all firing decisions to an advanced computer (but can override them if necessary). Why would you want to put a computer in charge? If you’re out at sea and an enemy fires 50 missiles at you all at once, you’d be very happy to have a system that can react much faster than a human could.

Army of None also shows that autonomy has great benefits in environments where humans can’t survive (such as flight situations with high G forces) or in which communications have broken down. It can be enormously helpful to have an unmanned drone, tank, or sub that carries out a clear, limited mission with little communication back and forth with human controllers.

In addition, autonomous weapons could potentially help save civilian lives. Scharre cites robotics experts who argue that “autonomous weapons … could be programmed to never break the laws of war…. They wouldn’t seek revenge. They wouldn’t get angry or scared. They would take emotion out of the equation. They could kill when necessary and then turn killing off in an instant.”

Despite these and other advantages, Scharre does not want the military ever to turn over judgment to computers. To make his case, he offers compelling real-life cases in which human judgment was essential for preventing needless killing, such as his own experiences in Afghanistan. “A young girl of maybe five or six headed out of the village and up our way, two goats in trail. Ostensibly she was just herding goats, but she [was actually] spotting for Taliban fighters.” Scharre’s unit did not shoot. Yes, it would have been legal, but he argues that it would not have been morally right. A robotic sniper following strict algorithms might well have opened fire the second it detected a radio in her hand.

Scharre ends the book by exploring the possibility of an international ban on fully autonomous weapons. He concludes that this kind of absolute ban is not likely to succeed. However, he holds out hope that enlightened self-interest could bring countries together to ban specific uses of autonomous weapons, such as those that target individual people. He also believes it’s feasible to establish non-binding rules of the road that could reduce the potential for autonomous systems to set each other off accidentally. He also believes we could update the international laws of war to embed a common principle for human involvement in lethal force.

There are no easy answers here. But I agree with Scharre that we have to guard against becoming “seduced by the allure of machines—their speed, their seeming perfection, their cold precision.” And we should not leave it up to military planners or the people writing software to determine where to draw the proper lines. We need many experts and citizens across the globe to get involved in this important debate.

In the early days of Microsoft, I felt pretty confident about my coding skills, but I had a lot to learn about project management. This became abundantly clear after an incident in 1978, when I told Intel—a really important customer—that we would deliver them a version of Microsoft BASIC in four weeks. They thought I was crazy to promise it that fast, and it turned out that they were right. We were two weeks late.

As it happens, Intel employed someone who would end up helping me improve my management skills: Andy Grove. A precise, hard-driving guy, Andy oversaw their strategy and operations, and he championed the idea of management by objective. Andy and I became friendly over the years, I studied several of the business books he wrote early on, and Microsoft adopted some of the methods that Intel used. I consider Andy one of the great business leaders of the 20^th century.

Andy’s ideas are a basis for the management system called OKRs (Objectives and Key Results) developed by John Doerr, a venture capitalist and a frequent business partner of mine. In his new book, Measure What Matters: How Google, Bono, and the Gates Foundation Rock the World With OKRs, John explains how OKRs work and shows how you can apply them in all sorts of situations.

I’d recommend John’s book for anyone interested in becoming a better manager (and I’d say that even if I hadn’t been interviewed for a super-nice chapter about the Gates Foundation). In the excerpt below, John tells the inside story of how Andy inspired the idea of OKRs.

Excerpt from Measure What Matters
By John Doerr

Intel was Grove’s laboratory for management innovation. He loved to teach, and the company reaped the benefits. A few days after getting hired, I received a coveted invitation to Intel’s Organization, Philosophy, and Economics course, known as iOPEC, a seminar on Intel strategy and operations. Resident professor: Dr. Andy Grove.

In the space of an hour, Grove traced the company’s history, year by year. He summarized Intel’s core pursuits: a profit margin twice the industry norm, market leadership in any product line it entered, the creation of “challenging jobs” and “growth opportunities” for employees. Fair enough, I thought, though I’d heard similar things at business school.

Then he said something that left a lasting impression on me. He referenced his previous company, Fairchild, where he’d first met Robert Noyce and Gordon Moore and went on to blaze a trail in silicon wafer research. Fairchild was the industry’s gold standard, but it had one great flaw: a lack of “achievement orientation.”

“Expertise was very much valued there,” Andy explained. “That is why people got hired. That’s why people got promoted. Their effectiveness at translating that knowledge into actual results was kind of shrugged off.” At Intel, he went on, “we tend to be exactly the opposite. It almost doesn’t matter what you know. It’s what you can do with whatever you know or can acquire and actually accomplish [that] tends to be valued here.” Hence the company’s slogan: “Intel delivers.”

It almost doesn’t matter what you know… To claim that knowledge was secondary and execution all-important—well, I wouldn’t learn that at Harvard. I found the proposition thrilling, a real-world affirmation of accomplishment over credentials. But Grove wasn’t finished, and he had saved the best for last. Over a few closing minutes, he outlined a system he’d begun to install in 1971, when Intel was three years old. It was my first exposure to the art of formal goal setting. I was mesmerized.

A few unvarnished excerpts, straight from the father of OKRs:

Now, the two key phrases…are objectives and the key result. And they match the two purposes. The objective is the direction: “We want to dominate the mid-range microcomputer component business.” That’s an objective. That’s where we’re going to go. Key results for this quarter: “Win ten new designs for the 8085” is one key result. It’s a milestone. The two are not the same…

The key result has to be measurable. But at the end you can look, and without any arguments: Did I do that or did I not do it? Yes? No? Simple. No judgments in it.

Now, did we dominate the mid-range microcomputer business? That’s for us to argue in the years to come, but over the next quarter we’ll know whether we’ve won ten new designs or not.

It was a “very, very simple system,” Grove said, knowing simplicity was catnip to an audience of engineers. On its face, the conception seemed logical, commonsensical—and inspiring. Against the stale management orthodoxy of the period, Grove had created something fresh and original. Strictly speaking, however, his “objectives and key results” did not spring from the void. The process had a precursor. In finding his way, Grove had followed the trail of a legendary, Vienna-born gadfly, the first great “modern” business management thinker: Peter Drucker.

Excerpted from Measure What Matters: How Google, Bono and the Gates Foundation Rock the Work with OKRs by John Doerr, in agreement with Portfolio, an imprint of Penguin Publishing Group, a division of Penguin Random House LLC. Copyright © 2018 by Bennet Group LLC.

I talk about the developed and developing world all the time, but I shouldn’t.

My late friend Hans Rosling called the labels “outdated” and “meaningless.” Any categorization that lumps together China and the Democratic Republic of Congo is too broad to be useful. But I’ve continued to use “developed” and “developing” in public (and on this blog) because there wasn’t a more accurate, easily understandable alternative—until now.

I recently read Hans’ new book Factfulness: Ten Reasons We're Wrong About the World—and Why Things Are Better Than You Think. In it, he offers a new framework for how to think about the world. Hans proposes four income groups:

• Level 1: One billion people live on level 1. This is what we think of as extreme poverty. If you’re on level 1, you survive on less than $2 a day and get around by walking barefoot. Your food is cooked over an open fire, and you spend most of your day traveling to fetch water. At night, you and your children sleep on a dirt floor.
• Level 2: Three billion people live on level 2, between $2 and $8 a day. Level 2 means that you can buy shoes and maybe a bike, so it doesn’t take so long to get water. Your kids go to school instead of working all day. Dinner is made over a gas stove, and your family sleeps on mattresses instead of the floor.
• Level 3: Two billion people live on level 3, between $8 and $32 a day. You have running water and a fridge in your home. You can also afford a motorbike to make getting around easier. Some of your kids start (and even finish) high school.
• Level 4: One billion people live on level 4. If you spend more than $32 a day, you’re on level 4. You have at least a high school education and can probably afford to buy a car and take a vacation once in a while.

This was a breakthrough to me. The framework Hans enunciates is one that took me decades of working in global development to create for myself, and I could have never expressed it in such a clear way. I’m going to try to use this model moving forward.

Why does it matter? It’s hard to pick up on progress if you divide the world into rich countries and poor countries. When those are the only two options, you’re more likely to think anyone who doesn’t have a certain quality of life is “poor.”

Hans compares this instinct to standing on top of a skyscraper and looking down at a city. All of the other buildings will look short to you whether they’re ten stories or 50 stories high. It’s the same with income. Life is significantly better for those on level 2 than level 1, but it’s hard to see that from level 4 unless you know to look for it.

The four levels are just one of many insights in Factfulness that will help you better understand the world. I’m excited that Hans’ publisher Flatiron Books plans to donate 5,000 copies to Books for Africa and Reader to Reader—two organizations that encourage reading in underserved communities. Hans worked on the book until his last days (even bringing several chapters with him in the ambulance to the hospital), and his son Ola and daughter-in-law Anna helped finish it after he passed.

The bulk of the book is devoted to ten instincts that keep us from seeing the world factfully. These range from the fear instinct (we pay more attention to scary things) to the size instinct (standalone numbers often look more impressive than they really are) to the gap instinct (most people fall between two extremes). With each one, he offers practical advice about how to overcome our innate biases. Gates Notes Insiders can get a free preview of the gap instinct chapter here:

Hans argues that these instincts make it difficult to put events in perspective. Imagine news coverage about a natural disaster—say, a tornado that kills 10 people in a small town. If you look at only the headlines, you’ll view the event as an unbearable tragedy (which it is). But if you put it in the context of history, you’ll also know that tornadoes today are a lot less deadly than they used to be, thanks to advanced warning systems. That’s no consolation to the loved ones of those who died, but it matters a great deal to everyone who survived the tornado.

In other words, the world can be both bad and better. That idea drives the work Melinda and I do every day, and Hans articulates it beautifully in Factfulness. It’s a great companion to Steven Pinker’s Enlightenment Now (although Hans is a little less academic than Pinker is). With rare exceptions, most of the miracles of humankind are long-term, constructed things. Progress comes bit by bit. We’ve cut the number of people living in extreme poverty by half over the last twenty years, but there was never a morning when “POVERTY RATES DROP INCREMENTALLY” dominated newspaper headlines.

Another remarkable thing about Factfulness—and about Hans himself—is that he refuses to judge anyone for their misconceptions. Most writers would beat people up for their ignorance, but he doesn’t. Hans even resists going after the media. Instead, he tells you about the history of his own ignorance. He explains that these instincts make us human, and that overcoming them isn’t easy.

That’s classic Hans. He was always kind, often patient, and never judgmental. He spent his life not only understanding how global health was improving but sharing what he learned in a fun, clear way with a broad set of people. If you never met Hans or watched one of his many TED talks, Factfulness will help you get a sense of why he was so special. I wish I could tell Hans how much I liked it. Factfulness is a fantastic book, and I hope a lot of people read it.

For years, I’ve been saying Steven Pinker’s The Better Angels of Our Nature was the best book I’d read in a decade. If I could recommend just one book for anyone to pick up, that was it. Pinker uses meticulous research to argue that we are living in the most peaceful time in human history. I’d never seen such a clear explanation of progress.

I’m going to stop talking up Better Angels so much, because Pinker has managed to top himself. His new book, Enlightenment Now, is even better.

Enlightenment Now takes the approach he uses in Better AngelsBetter Angels to track violence throughout history and applies it to 15 different measures of progress (like quality of life, knowledge, and safety). The result is a holistic picture of how and why the world is getting better. It’s like on steroids.

Pinker was generous enough to send me an early copy, even though Enlightenment Now won’t be released until the end of February. I read the book slowly since I loved it so much, but I think most people will find it a quick and accessible read. He manages to share a ton of information in a way that’s compelling, memorable, and easy to digest.

It opens with an argument in favor of returning to the ideals of the Enlightenment—an era when reason, science, and humanism were touted as the highest virtues. (Gates Notes Insiders can get a preview of this section of the book.)

I’m all for more reason, science, and humanism, but what I found most interesting were the 15 chapters exploring each measure of progress. Pinker is at his best when he analyzes historic trends and uses data to put the past into context. I was already familiar with a lot of the information he shares—especially about health and energy—but he understands each subject so deeply that he’s able to articulate his case in a way that feels fresh and new.

I love how he’s willing to dive deep into primary data sources and pull out unexpected signs of progress. I tend to point to things like dramatic reductions in poverty and childhood deaths, because I think they’re such a good measure of how we’re doing as a society. Pinker covers those areas, but he also looks at more obscure topics. 

Here are five of my favorite facts from the book that show how the world is improving:

1. You’re 37 times less likely to be killed by a bolt of lightning than you were at the turn of the century—and that’s not because there are fewer thunderstorms today. It’s because we have better weather prediction capabilities, improved safety education, and more people living in cities.
2. Time spent doing laundry fell from 11.5 hours a week in 1920 to an hour and a half in 2014. This might sound trivial in the grand scheme of progress. But the rise of the washing machine has improved quality of life by freeing up time for people—mostly women—to enjoy other pursuits. That time represents nearly half a day every week that could be used for everything from binge-watching Ozark or reading a book to starting a new business.
3. You’re way less likely to die on the job. Every year, 5,000 people die from occupational accidents in the U.S. But in 1929—when our population was less than two-fifths the size it is today—20,000 people died on the job. People back then viewed deadly workplace accidents as part of the cost of doing business. Today, we know better, and we’ve engineered ways to build things without putting nearly as many lives at risk.
4. The global average IQ score is rising by about 3 IQ points every decade. Kids’ brains are developing more fully thanks to improved nutrition and a cleaner environment. Pinker also credits more analytical thinking in and out of the classroom. Think about how many symbols you interpret every time you check your phone’s home screen or look at a subway map. Our world today encourages abstract thought from a young age, and it’s making us smarter.
5. War is illegal. This idea seems obvious. But before the creation of the United Nations in 1945, no institution had the power to stop countries from going to war with each other. Although there have been some exceptions, the threat of international sanctions and intervention has proven to be an effective deterrent to wars between nations.

Pinker also tackles the disconnect between actual progress and the perception of progress—something I’ve spent a lot of time thinking about. People all over the world are living longer, healthier, and happier lives, so why do so many think things are getting worse? Why do we gloss over positive news stories and fixate on the negative ones? He does a good job explaining why we’re drawn to pessimism and how that instinct influences our approach to the world, although I wish he went more in depth about the psychology (especially since he’s a psychologist by training). The late Hans Rosling explains this more fully in his excellent new book Factfulness, which I plan to review soon.

I agree with Pinker on most areas, but I think he’s a bit too optimistic about artificial intelligence. He’s quick to dismiss the idea of robots overthrowing their human creators. While I don’t think we’re in danger of a Terminator-style scenario, the question underlying that fear—who exactly controls the robots?—is a valid one. We’re not there yet, but at some point, who has AI and who controls it will be an important issue for global institutions to address.

The big questions surrounding automation are proof that progress can be a messy, sticky thing—but that doesn’t mean we’re headed in the wrong direction. At the end of Enlightenment Now, Pinker argues that “we will never have a perfect world, and it would be dangerous to seek one. But there is no limit to the betterments we can attain if we continue to apply knowledge to enhance human flourishing."

The world is getting better, even if it doesn’t always feel that way. I’m glad we have brilliant thinkers like Steven Pinker to help us see the big picture. Enlightenment Now is not only the best book Pinker’s ever written. It’s my new favorite book of all time.

In Atlanta earlier this year, Melinda and I met a young woman I’ll call Sharon. (That’s not her real name.) Sharon works 12 hours a day, seven days a week. She is a single mom with two sons, including a newborn. While Sharon was in the hospital after the birth of her new son, she missed a single rent payment on her apartment. She came home to discover that she was being evicted.

When we met, Sharon was still fighting the eviction and getting help from a legal aid group. But it was clear she was in crisis. It broke our hearts to hear what she and her boys were going through.

Meeting Sharon put a face and name on an issue I had been thinking about a lot. Just a few days before we met, I finished reading Evicted: Poverty and Profit in the American City, by Matthew Desmond, a sociologist at Princeton University and a grantee of our foundation. I can see why Desmond received one of the MacArthur Foundation’s “genius” grants and won a Pulitzer for his book. His research shows that experiences like Sharon’s are not some aberration. Hundreds of thousands—and maybe millions—of Americans are evicted from their homes every year. In Milwaukee, where Desmond did his reporting, one in eight renters were forced to move in a two-year period.

As stunning as those numbers are, Evicted is primarily about people, not data. Desmond has written a brilliant portrait of Americans living in poverty. I have no personal experience with the kind of crisis faced by Sharon or the people profiled in , so I can only learn about it by hearing their stories. This book gave me a better sense of what it is like to be very poor in this country than anything else I have read.

Desmond spent 18 months living in two high-poverty neighborhoods in Milwaukee—one mostly white, the other mostly black—getting to know the residents and documenting their lives. You meet both landlords and renters, and he portrays them all without being the least bit judgmental. He just helps you understand why they make the choices they make. Although the specifics of their lives are unlike anything I have experienced, Desmond makes it easy to empathize with them.

True to its title, much of Evicted is about how hard it is to find and keep a home when you live in deep poverty. Most experts agree that the ideal is to spend no more than 30 percent of your income on housing; according to Desmond’s research, most poor families have to spend over 50 percent on housing, and for many it’s over 70 percent.

When you’re paying so much to keep a roof over your head, there’s no room for bad luck. A single bad incident can send you reeling. One woman in the book, Arleen, gets evicted from her apartment after someone breaks down her front door over a minor dispute involving kids throwing snowballs. Another time, she falls irreparably behind on the rent after helping to pay for the funeral of a close friend.

For me, though, Evicted’s biggest contribution isn’t the focus on housing. It’s the dramatic illustration of the ways in which issues of poverty are intertwined. When someone has to search for a new place to live, they miss work, which cuts back on their pay and makes them more likely to get fired. And all this instability has a terrible impact on children. One of Arleen’s sons attends five different schools in a single year.

I also got a glimpse of how gut-wrenching it must be when someone piles up your belongings on the curb and you don’t know where your family is going to sleep that night. It’s no wonder that people who have been evicted experience significantly higher rates of depression and anxiety.

As Desmond puts it: “Eviction’s fallout is severe. Losing a home sends families to shelters, abandoned houses, and the street. It invites depression and illness, compels families to move into degrading housing in dangerous neighborhoods, uproots communities, and harms children. Eviction reveals people’s vulnerability and desperation, as well as their ingenuity and guts.”

Melinda and I have been working for some time to learn more about how Americans move up the economic ladder (what experts call mobility from poverty). Evicted helped me understand one piece of that very complex question, and it made me want to learn more about the systemic problems that make housing unaffordable, as well as the various government programs designed to help.

Desmond briefly goes over the history of public housing. Big government-run projects are largely a thing of the past, and today most poor people live in private housing. But because funding hasn’t kept up with the need, he writes, only about a quarter of families that qualify for help paying their rent actually get any. The wait list for a housing voucher is often measured not in months or even years, but in decades.

(If you’re interested in reading more about how these problems disproportionately affect African-Americans—and in the role that legal segregation has played—I strongly recommend reading The Color of Law, by Richard Rothstein. I was stunned by the huge role that federal policy has played in creating segregated housing patterns.)

Evicted raises one big question that it doesn’t really answer: How can low-income neighborhoods have cheap real estate and vacant houses, but still lack decent affordable homes? As Desmond notes, the average rent for a two-bedroom apartment in Milwaukee’s highest-poverty areas was only $50 less than the citywide median. But he doesn’t say a lot about what causes this, for example how restrictive zoning and strict building codes may drive up the cost of even a modest home.

To be fair, there’s a lot that we simply don’t know about this question. There isn’t good data on this subject. So Desmond has set out to learn more. With support from our foundation, he is calculating eviction rates for every city in the country. He is looking deeper into these market failures to understand why housing prices stay so high even in low-income neighborhoods. (We funded this work long before I read Evicted.)

I am eager to see what Desmond’s research discovers. In the meantime, Evicted is well worth reading for anyone who wants to better understand poverty in America. It is beautifully written, thought-provoking, and unforgettable. 

What gives our lives meaning? And what if one day, whatever gives us meaning went away—what would we do then?

I’m still thinking about those weighty questions after finishing Homo Deus, the provocative new book by Yuval Noah Harari.

Melinda and I loved Harari’s previous book, Sapiens, which tries to explain how our species came to dominate the Earth. It sparked conversations over our dinner table for weeks after we both read it. So when Homo Deus came out earlier this year, I grabbed a copy and made sure to take it on our most recent vacation.

I’m glad I did. Harari’s new book is as challenging and readable as Sapiens. Rather than looking back, as does, it looks to the future. I don’t agree with everything the author has to say, but he has written a thoughtful look at what may be in store for humanity.

Homo Deus argues that the principles that have organized society will undergo a huge shift in the 21^st century, with major consequences for life as we know it. So far, the things that have shaped society—what we measure ourselves by—have been some combination of religious rules about how to live a good life, and more earthly goals like getting rid of sickness, hunger, and war. We have organized to meet basic human needs: being happy, healthy, and in control of the environment around us. Taking these goals to their logical conclusion, Harari says humans are striving for “bliss, immortality, and divinity.”

What would the world be like if we actually achieved those things? This is not entirely idle speculation. War and violence are at historical lows and still declining. Advances in science and technology will help people live much longer and go a long way toward ending disease and hunger.

Here is Harari’s most provocative idea: As good as it sounds, achieving the dream of bliss, immortality, and divinity could be bad news for the human race. He foresees a potential future where a small number of elites upgrade themselves through biotechnology and genetic engineering, leaving the masses behind and creating the godlike species of the book’s title; where artificial intelligence “knows us better than we know ourselves”; and where these godlike elites and super-intelligent robots consider the rest of humanity to be superfluous.

Harari does a great job of showing how we might arrive at this grim future. But I am more optimistic than he is that this future is not pre-ordained.

He argues that humanity’s progress toward bliss, immortality, and divinity is bound to be unequal—some people will leap ahead, while many more are left behind. I agree that, as innovation accelerates, it doesn’t automatically benefit everyone. The private market in particular serves the needs of people with money and, left to its own devices, often misses the needs of the poor. But we can work to close that gap and reduce the time it takes for innovation to spread. For example, it used to take decades for lifesaving vaccines developed in the rich world to reach the poor. Now—thanks to efforts by pharmaceutical companies, foundations, and governments—there are cases where that lag time is less than a year. We should try to narrow the gap even more, but the larger point is clear: Inequity is not inevitable.

In addition, in my view, the robots-take-over scenario is not the most interesting one to think about. It is true that as artificial intelligence gets more powerful, we need to ensure that it serves humanity and not the other way around. But this is an engineering problem—what you could call the control problem. And there is not a lot to say about it, since the technology in question doesn’t exist yet.

I am more interested in what you might call the purpose problem. Assume we maintain control. What if we solved big problems like hunger and disease, and the world kept getting more peaceful: What purpose would humans have then? What challenges would we be inspired to solve?

In this version of the future, our biggest worry is not an attack by rebellious robots, but a lack of purpose.

I think of this question in terms of my own life. My family gives my life purpose—being a good husband, father, and friend. Like every parent, I want my children to lead happy, healthy, fulfilling lives. But what if such a life was guaranteed for every child on Earth? How would that change the role parents play?

Harari does the best job I have seen of explaining the purpose problem. And he deserves credit for venturing an answer to it. He suggests that finding a new purpose requires us to develop new religion—using the word in a much broader sense than most people do, something like “organizing principles that direct our lives.”

Unfortunately, I wasn’t satisfied by his answer to the purpose question. (To be fair, I haven’t been satisfied by the answers I have seen from other smart thinkers like Ray Kurzweil and Nick Bostrom, or by my own answers either.) In the book’s final section, Harari talks about a religion he calls Dataism, in which the greatest moral good is to increase the flow of information. Dataism “has nothing against human experiences,” he writes. “It just doesn’t think they have intrinsic value.” The problem is that Dataism doesn’t really help organize people’s lives, because it doesn’t account for the fact that people will always have social needs. Even in a world without war or hunger or disease, we would still value helping, interacting with, and caring for each other.

But don’t let a dissatisfying conclusion dissuade you from reading Homo Deus. It is a deeply engaging book with lots of stimulating ideas and not a lot of jargon. It makes you think about the future, which is another way of saying it makes you think about the present. I recommended it to Melinda and she is reading it as I write this review. I can’t wait to talk with her about it over dinner.

I am not a self-made man. My parents started me off in life with every possible advantage—from great schools to constant encouragement to patience with my many quirks.

So the disadvantaged world J.D. Vance describes in his terrific, heartbreaking book Hillbilly Elegy is one that I know only vicariously. Vance grew up in Appalachian Ohio and Kentucky, in poor white communities where family strife was a constant, work was not, and even many pawnshops had closed their doors.

So imagine what it was like for him when he managed—through the high expectations of his grandparents, the discipline of the Marines, and his own big brain—to get himself into Yale Law School. Suddenly he began experiencing life not as the “abandoned son of a man I hardly knew and a woman I wished I didn’t” but as a highly sought-after member of one of America’s most elite institutions. He was a stranger in a strange land.

At Yale, recruiters from law firms similar to the one my dad started were beating a path to his door. “Two years earlier, I had applied to dozens of places in the hope of landing a well-paying job after college but was rebuffed every time,” Vance writes. “After only a year at Yale Law, my classmates and I were being handed six-figure salaries by men who had argued before the United States Supreme Court.”

Through deeply personal stories like these, Hillbilly Elegy sheds light our nation’s vast cultural divide—a topic that has become far more relevant than Vance ever dreamed when he was writing this book.

I was eager to read Hillbilly Elegy not just because of the now-apparent implications for American politics. Melinda and I have been working for several years to learn more about how Americans move up from the lowest rungs of the economic ladder (what experts call mobility from poverty). Even though doesn’t use a lot of data, I came away with new insights into the multifaceted cultural and family dynamics that contribute to poverty.

The fact that Hillbilly Elegy is not just an important read but also a great one came as a bit of a surprise to me. There are no big cliffhangers and no “how will it end?”-type mystery propelling this story. We know from the outset that the narrator survives his chaotic, mostly fatherless childhood and lands at Yale Law School.

I think the book was such a good read in part because of Vance’s bravery. Vance learns early in life that there is “no greater disloyalty than class betrayal.” Yet by writing this book he risks being called a traitor by portraying a culture that, in his view, is suffering from self-inflicted wounds.

The bravest part of the book is the part where he acknowledges that his upbringing haunts his own marriage. “Even at my best, I’m a delayed explosion—I can be defused, but only with skill and precision.... In my worst moments, I convince myself that there is no exit.”

Another element that makes this book so readable is the cast of characters. My favorites are Vance’s grandparents, Mamaw and Papaw. In a scene that takes place before Vance was born, Mamaw finally gets fed up with her husband’s violent drunkenness and tells him that she’ll kill him if he ever comes home drunk again. When Papaw ignores her, “Mamaw, never one to tell a lie, calmly retrieved a gasoline canister from the garage, poured it all over her husband, lit a match, and dropped it on his chest…. Miraculously, Papaw survived the episode with only minor burns.”

While lighting your husband on fire is nothing to admire, Mamaw is usually tough in the right way. Vance can’t count the number of times he had to flee to Mamaw’s house to escape his mother’s dysfunction. “Mamaw was the best thing that ever happened to me,” he writes. She spent the last two decades of her life “showing me the value of love and stability.”

Another guardian angel is Vance’s half-sister Lindsay, who is five years older. “During explosive fights between Mom and whatever man she let into our home, it was Lindsay who withdrew to her bedroom to place a rescue call to Mamaw and Papaw. She fed me when I was hungry, changed my diaper when no one else did, and dragged me everywhere with her—even though … I weighed nearly as much as she did.” Papaw once called Lindsay “the one true adult in the house.”

To Vance’s credit, he doesn’t pretend to be a policy expert and doesn’t offer simplistic solutions. But of course as I read the book I thought about what can be done to empower and create opportunity in poor communities, rural and urban alike. The key take-home for me is that whatever else we do to address the complex realities of poverty in America, we must find more ways to surround children with high expectations and as many loving and caring adults as possible. 

Most casual observers of history probably don’t have a great deal of familiarity with the story of Adolfo Suárez.

But to read Archie Brown’s fascinating book, The Myth of the Strong Leader, is to see an illustration that leaders like Suárez, who served as prime minister of Spain from 1976 to 1981, possess leadership styles and capacities that are incredibly effective, and depressingly rare.

After General Francisco Franco’s death in 1975, tensions were high. The country had just emerged from nearly four decades of authoritarianism, and faced a number of possible futures—many of them bloody. Suárez, who had come from the right-wing Franco regime, could have tried to rule through intimidation and exclusion. Instead, he made it a priority to bring the left-wing leaders of the Communist and Socialist parties into the fold. Through negotiation, persuasion, and some very adroit coalition-building, he convinced those around him of the importance of democracy and pluralism, staving off a military coup and eventually creating the constitutional monarchy that exists today. At one point, Suárez convinced the parliament that was appointed under Franco—at that time, the “old elite”—to abolish itself to make way for elected parties. For scholars of leadership, it’s hard to imagine a better illustration of skill than that.

The story of Suárez is one of a series of case studies that animate Brown’s book and make it an important and unusual read. Whereas most books about political leadership are chronologies, mapping the rise and fall of leaders over time, this one is more of a taxonomy. Brown takes a deep look at the traits and tendencies leaders exhibit, and the categories they fall into, as a way of understanding the egos, motivations, and behaviors responsible for so much progress, and so much suffering, in the world. Throughout, he presents a new way to think about today’s challenges—and the people we entrust with solving them.

Brown’s core argument is exactly what his title suggests: despite a worldwide fixation on strength as a positive quality, strong leaders—those who concentrate power and decision-making in their own hands—are not necessarily good leaders. On the contrary, Brown argues that the leaders who make the biggest difference in office, and change millions of lives for the better, are the ones who collaborate, delegate, and negotiate—the ones who recognize that no one person can or should have all the answers.

To make his case, Brown sorts successful leaders into two categories. “Redefining” leaders radically change the political landscape, not by “[seeking] centre ground” but by “[moving] the centre in their direction.” Brown puts Franklin Delano Roosevelt and Lyndon Baines Johnson in this category, because several of their signature achievements—FDR’s New Deal, and LBJ’s War on Poverty and dedication to civil rights—have had a major and lasting impact on American society. We tend to think of these men as strong leaders, and in many ways we’re right. But Brown shows a different side of the story: because of the checks and balances of the American political system, neither FDR nor LBJ had the ability to govern by fiat. Their strength lay in their power to persuade—to convince their colleagues in government, and the American people, to understand and support their point of view.

“Transformational” leaders, Brown argues, go a step further, by fundamentally transforming the political or economic system itself. If you’re dismayed at how rare it is for an American president to reshape our political or economic system, as many voters today seem to be, consider that the last transformational American leader, in Brown’s analysis, was Abraham Lincoln. Transformational leaders are the ones, like Suárez, who leave their country a completely different place than they found it. In this category, Brown lists Charles de Gaulle, Mikhail Gorbachev, Deng Xiaoping, and Nelson Mandela.

We don’t need to look far to find evidence of the overwhelming tendency to equate strong leadership with good leadership. As Brown puts it, think about the last time you heard someone say, “What we need is a weak leader.”

Brown does a wonderful job of showing how the same qualities that seem so appealing in strong leaders can lead, in the mildest cases, to bad decisions—and, in the most extreme cases, to death and suffering on a massive scale. These qualities can be boiled down to a belief, on the part of the leader, that he or she—and usually he—is the only one who knows what the country needs, and the only one who can deliver it.

The danger of this kind of thinking is obvious when you consider some of the examples Brown features: Hitler, Stalin, Mussolini, and Mao. Though their stories are notorious, it’s well worth reading Brown’s insightful analysis of each man’s rise and reign.

But some of the most fascinating profiles in the book are of leaders on the other end of the spectrum—the ones you probably didn’t dwell on in history class. These leaders didn’t insist on their own infallibility or claim exclusive power over policy decisions. And yet they pulled off incredible feats of leadership simply by working with others and seeking advice when they needed it.

Though The Myth of the Strong Leader is about political leadership, you come away from Brown’s analysis with a deeper understanding of leadership in general.

Through my work in the business world and at the foundation, I’ve seen firsthand how ineffective and even dangerous it can be when leaders make decisions alone—and how much good we can do when we work together. Good leaders will challenge themselves, bring in fresh thinking and expert advice, and not only invite but seriously consider opposing viewpoints.

In our foundation’s work in the global health space, we see issue after issue that can’t be addressed by a single leader, no matter how strong. Take the example of polio eradication. For decades, polio ravaged India—and the conventional thinking was that the country was simply too big, its rural communities too remote, and its poverty too widespread for the virus to be stopped. But in 2012, the government of India, working closely with the global health community, beat the odds. A massive vaccination campaign mobilized 2 million volunteers, community leaders, and frontline health workers who improvised and innovated, refusing to leave a single child behind. UNICEF helped coordinate. WHO helped track the virus and vaccine supplies. My colleagues at the foundation, working with the Rotary International and the CDC, lent additional support and expertise. In the end, the effort took the kind of leadership Suárez and others exhibited so clearly: collaboration, humility, and a willingness to listen.

Whether we’re avid political scientists or not, we can learn a lot from Brown’s analysis of leadership. 

I took a lot of math classes in college. I remember Professor Shlomo Sternberg getting up on the first day of his class and telling us we weren’t going to see any numbers other than 0, 1, and 2. I had a great time in that one.

Jordan Ellenberg, the author of How Not to Be Wrong: The Power of Mathematical Thinking, studied under Sternberg, but I think I’d like his book even if we didn’t have that in common. On the surface it’s about math, but it’s really about how much math plays into our daily lives without our even knowing it.

The book starts with a story about Abraham Wald, an Eastern European mathematician who worked for the American government during World War II. One day the military came to him and said, “We have a problem. We send our planes overseas, and when they come back, their engines are fine, but their tails are riddled with bullet holes. If we put more armor on the tails, though, the planes get too heavy to fly. Can you help us figure out how to protect the planes’ tails better?”

And he said, “No.”

They were surprised, but then he explained that they were asking the wrong question. “You need to put more armor where there aren’t bullet holes. Clearly, when the plane gets hit in the tail, it makes it back to you. Your problem is the planes that get hit in the engine, because those are the ones that aren’t coming back.”

Ultimately, that’s really what the book is: a series of stories about how a lot of the apparently non-mathematical systems that underpin our daily lives are actually deeply mathematical, and people couldn’t develop them until they started asking the right questions. Each chapter starts somewhere that seems fairly straightforward—electoral politics, say, or the Massachusetts lottery—and then uses that as a jumping-off point to talk about the math involved.

In some places the math gets quite complicated. Ellenberg deals with cutting-edge thinking about subjects like prime numbers, extra dimensions, and relative infinities. A non-mathematician might get a little lost along the way. But even if you don’t feel like following him all the way to the bottom of things like Fano planes, 24-dimensional spheres, and Condorcet’s paradox, after he goes really deep he always comes back to make sure you’re still with him.

The way he deals with the lottery is a great example. For several years, the Massachusetts lottery ran in a way that allowed three teams—one led by an MIT student, one by a medical researcher, and one by a guy from Michigan—to game the system and win millions of dollars. You might ask, How could the state let them cheat like that for so long? Part of the answer is, the state didn’t care. Massachusetts got 80 cents for every $2 lottery ticket sold, no matter who won. And the second part of the answer is, they weren’t cheating. They were taking advantage of math to give themselves slightly better odds at winning and other people slightly worse odds. They basically turned themselves into the house at a casino.

But Ellenberg extends his analysis even further, because while two of the teams just had the Quic Pic machine choose their numbers randomly, the team of students filled out its tickets by hand. Tens of thousands of tickets, every time they played! Ellenberg has mathematical explanations for the difference—filling out the tickets by hand exposed the students to less risk of losing money in any given week—and then points out that, if you’re on a student’s budget, the thought of losing any money at all is pretty scary.

Toward the end of each chapter, Ellenberg broadens from these specific examples to a series of questions about how else some of the ideas in the chapter might be used, what kinds of mathematical questions are left to answer, and what kinds of real-life problems they might eventually solve.

Given how black-and-white so much of our political dialogue has become, I think it’s great to have somebody advocating for looking at the numbers, explaining the relative costs of things like alternative tax policies or what happens when you implement different voting strategies. Even if you don’t follow the deepest math behind these things, you can still appreciate the argument and the rigor of the thinking, and the world can always use more rigorous thinking.

The writing is funny, smooth, and accessible—not what you might expect from a book about math. What Ellenberg has written is ultimately a love letter to math. If the stories he tells add up to a larger lesson, it’s that “to do mathematics is to be, at once, touched by fire and bound by reason”—and that there are ways in which we’re all doing math, all the time.

Even as my glasses have gotten smaller and hopefully cooler over the years, I am still a proud member of Nerd Nation. As such, I read a lot of books—usually more than 50 a year. Many of the books I review on Gates Notes are recent releases, because I figure people are generally more interested in hearing about newer works. But I also like to revisit older books that feel especially important or relevant. Mindset: The New Psychology of Success (2006), by the Stanford psychologist Dr. Carol Dweck, is one of those books.

Mindset first came to my attention a few years ago in a fascinating invention session on education with my friend Nathan Myhrvold, similar to the sessions Malcolm Gladwell described in his article “In the Air: Who says big ideas are rare?” Dweck’s research had a big impact on our thinking that day. And in the years since, Dweck and her research have helped my foundation colleagues and me understand more about the attitudes and habits that allow some students to persevere in school despite big challenges.

Here is Dweck’s thesis: Our genes influence our intelligence and talents, but these qualities are not fixed at birth. If you mistakenly believe that your capabilities derive from DNA and destiny, rather than practice and perseverance, then you operate with what Dweck calls a “fixed mindset” rather than a “growth mindset.” Our parents and teachers exert a big influence on which mindset we adopt—and that mindset, in turn, has a profound impact on how we learn and which paths we take in life.   

In experiment after experiment, Dweck has shown that the fixed mindset is a huge psychological roadblock—regardless of whether you feel you were blessed with talent or not. If you have the fixed mindset and believe you were blessed with raw talent, you tend to spend a lot of time trying to validate your “gift” rather than cultivating it. To protect your self-identity as someone who’s super smart or gifted, you often steer clear of tough challenges that might jeopardize that identity. Here’s how Dweck puts it: “From the point of view of the fixed mindset, effort is only for people with deficiencies…. If you’re considered a genius, a talent, or a natural—then you have a lot to lose. Effort can reduce you.”

If you have the fixed mindset and believe you lost the genetic lottery, you also have little incentive to work hard. Why bother putting in a lot of effort to learn a difficult concept if you’ve convinced yourself that you’re lousy at it and nothing is going to alter that basic equation? When I was visiting with community college students in Arizona, one young man said to me, “I’m one of the people who’s not good at math.” It kills me when I hear that kind of thing. I think about how different things might have been if he had been told consistently “you’re very capable of learning this stuff.”

In contrast, people with the growth mindset believe that basic qualities, including intelligence, can be strengthened like muscles. It’s not that they believe that anyone can become the next Albert Einstein or Michael Jordan if they just work hard enough on their physics homework or fadeaway jumpers. Instead, in Dweck’s words “they believe a person’s true potential is unknown (and unknowable); that it’s impossible to foresee what can be accomplished with years of passion, toil, and training.” As a result, they have every incentive to take on tough challenges and seek out opportunities to improve. 

One of the reasons I loved Mindset is because it’s solutions-oriented. In the book’s final chapter, Dweck describes the workshop she and her colleagues have developed to shift students from a fixed to a growth mindset. These workshops demonstrate that “just learning about the growth mindset can cause a big shift in the way people think about themselves and their lives.”

My only criticism of the book is that Dweck slightly oversimplifies for her general audience. Contrary to the impression that Dweck creates here (but probably not in her academic papers), most of us are not purely fixed-mindset people or growth-mindset people. We’re both. When I was reading the book, I realized that I have approached some things with a growth mindset (like bridge) while other things in a fixed mindset (like basketball).

The greatest virtue of the book is that you can’t help but ask yourself things like, “Which areas have I always looked at through a fixed-mindset lens?” and “In what ways am I sending the wrong message to my children about mindset and effort?” Thanks to Dweck’s skillful coaching, you’re almost guaranteed to approach these tough questions with a growth mindset.

I turned 60 at the end of October. Like a lot of people who reach that milestone, I got to thinking about the “résumé virtues” (the traits that drive external success) and the “eulogy virtues” (the qualities that lead to deeper meaning)—and finding the right balance between the two.

My birthday was not the only reason I started thinking about these questions. I was also prompted by reading The Road to Character, the latest book by New York Times columnist David Brooks. Brooks sums up his aspiration for the book this way: “I’m hoping you and I will both emerge from the next nine chapters slightly different and slightly better.” It certainly was a stimulating read, and it got me thinking about my own motivations and limitations in new ways.

The central metaphor of the book comes from the Book of Genesis. Borrowing from a rabbi named Joseph Soleveitchik, Brooks points out that Genesis contains two opposing depictions of Adam, which represent two different sides of human nature. “Adam I is the career-oriented, ambitious side of our nature,” Brooks writes. “He wants to have high status and win victories.” Adam II, in contrast, is more internally focused. “Adam II wants to have a serene inner character, a quiet but solid sense of right and wrong—not only to do good, but to be good.”

Brooks fleshes out the Adam I/Adam II metaphor by offering profiles of a broad set of historical figures. Not all of them are paragons of virtue. But they are paragons of character.

Many of the profiles gave me good food for thought. For example, I liked the profile of General George Marshall, who is probably better known today for his visionary plan to rebuild Europe after World War II than for leading the U.S. Army through that war. Brooks shows that Marshall was a man whose résumé accomplishments were built on a eulogy virtue: self-mastery, more commonly known as self-restraint or self-discipline.

The ultimate example of Marshall’s self-mastery came in the middle of the war, when President Franklin Roosevelt had to pick a commander of the Allied invasion of France. Brooks writes that “Marshall secretly craved the assignment.” And yet he refused to be a self-promoter. He didn’t even request the job when FDR asked him point blank if he wanted it. FDR wound up giving the assignment to Dwight Eisenhower, who rode his D-Day glory all the way to the White House. It’s hard to imagine a lot of people taking Marshall’s approach today, whether they’re in the military, politics, or business.

My least-favorite profile was of Augustine, a theologian born in the 4^th century AD. One of my friends found this profile to be a compelling one, but I didn’t buy it. Although more than a hundred of Augustine’s books and essays have survived to this day, I question how much we can really know about someone who lived that long ago.

After finishing his chronicles of character, Brooks uses his final chapter to warn that American society has drifted out of balance. He’s not trying to scold us into renouncing our worldly ways and becoming modern-day Augustines. And he certainly doesn’t believe that our Adam I side is evil. Far from it. He’s a free-market Republican who knows our Adam I traits are essential for driving the creativity, innovation, risk taking, and job creation that have made America great. But he argues that many forces in our economic and cultural life—including our intensely competitive meritocracy and social media platforms that nudge us all to be self-promoters—have made it harder to hear the voice of Adam II.

Brooks believes that this balance shift takes a psychic toll. “The central fallacy of modern life is the belief that accomplishments of the Adam I realm can produce deep satisfaction,” he writes. “Adam I’s desires are infinite and always leap out ahead of whatever has just been achieved. Only Adam II can experience deep satisfaction.”

I like the way Brooks fleshes out the Adam I and Adam II sides of human nature, but it’s not always clear where one starts and the other stops. For example, you could argue that my work with Microsoft was a classic case of Adam I résumé-building. But I found deep satisfaction in that work—not because I achieved material success beyond my wildest expectations, but because I got to help build a great team and be part of a new industry that unleashed the potential of people all around the world.

On the other hand, some might see my foundation work as based on eulogy virtues. But I would be lying if I said that I don’t also get a small boost of Adam I-type satisfaction when that work goes well.

Even if the distinction between résumé and eulogy—Adam I and Adam II—isn’t always crystal-clear, I agree with Brooks that it’s useful to think about how to get the balance right. In a chapter entitled “The Summoned Self,” he suggests that the voice of Adam II gets louder when we ask “What are my circumstances calling me to do?” He quotes an even more powerful version of this question from the novelist Frederick Buechner: “At what points do my talents and deep gladness meet the world’s deep need?”

I like that question a lot. It’s the kind of question we can ask any day, not just on those milestone birthdays. It can remind us to pay attention to our neighbors around the world. It can also help us hear the voice of Adam II.

Not long after I first met Warren Buffett back in 1991, I asked him to recommend his favorite book about business. He didn’t miss a beat: “It’s Business Adventures, by John Brooks,” he said. “I’ll send you my copy.” I was intrigued: I had never heard of or John Brooks.

Today, more than two decades after Warren lent it to me—and more than four decades after it was first published—Business Adventures remains the best business book I’ve ever read. John Brooks is still my favorite business writer. (And Warren, if you’re reading this, I still have your copy.)

A skeptic might wonder how this out-of-print collection of New Yorker articles from the 1960s could have anything to say about business today. After all, in 1966, when Brooks profiled Xerox, the company’s top-of-the-line copier weighed 650 pounds, cost $27,500, required a full-time operator, and came with a fire extinguisher because of its tendency to overheat. A lot has changed since then.

It’s certainly true that many of the particulars of business have changed. But the fundamentals have not. Brooks’s deeper insights about business are just as relevant today as they were back then. In terms of its longevity, Business Adventures stands alongside Benjamin Graham’s The Intelligent Investor, the 1949 book that Warren says is the best book on investing that he has ever read.

Brooks grew up in New Jersey during the Depression, attended Princeton University (where he roomed with future Secretary of State George Shultz), and, after serving in World War II, turned to journalism with dreams of becoming a novelist. In addition to his magazine work, he published a handful of books, only some of which are still in print. He died in 1993.

As the journalist Michael Lewis wrote in his foreword to Brooks’s book The Go-Go Years, even when Brooks got things wrong, “at least he got them wrong in an interesting way.” Unlike a lot of today’s business writers, Brooks didn’t boil his work down into pat how-to lessons or simplistic explanations for success. (How many times have you read that some company is taking off because they give their employees free lunch?) You won’t find any listicles in his work. Brooks wrote long articles that frame an issue, explore it in depth, introduce a few compelling characters, and show how things went for them.

In one called “The Impacted Philosophers,” he uses a case of price-fixing at General Electric to explore miscommunication—sometimes intentional miscommunication—up and down the corporate ladder. It was, he writes, “a breakdown in intramural communication so drastic as to make the building of the Tower of Babel seem a triumph of organizational rapport.”

In “The Fate of the Edsel,” he refutes the popular explanations for why Ford’s flagship car was such a historic flop. It wasn’t because the car was overly poll-tested; it was because Ford’s executives only pretended to be acting on what the polls said. “Although the Edsel was supposed to be advertised, and otherwise promoted, strictly on the basis of preferences expressed in polls, some old-fashioned snake-oil selling methods, intuitive rather than scientific, crept in.” It certainly didn’t help that the first Edsels “were delivered with oil leaks, sticking hoods, trunks that wouldn’t open, and push buttons that…couldn’t be budged with a hammer.”

One of Brooks’s most instructive stories is “Xerox Xerox Xerox Xerox.” (The headline alone belongs in the Journalism Hall of Fame.) The example of Xerox is one that everyone in the tech industry should study. Starting in the early ’70s, the company funded a huge amount of R&D that wasn’t directly related to copiers, including research that led to Ethernet networks and the first graphical user interface (the look you know today as Windows or OS X).

But because Xerox executives didn’t think these ideas fit their core business, they chose not to turn them into marketable products. Others stepped in and went to market with products based on the research that Xerox had done. Both Apple and Microsoft, for example, drew on Xerox’s work on graphical user interfaces.

I know I’m not alone in seeing this decision as a mistake on Xerox’s part. I was certainly determined to avoid it at Microsoft. I pushed hard to make sure that we kept thinking big about the opportunities created by our research in areas like computer vision and speech recognition. Many other journalists have written about Xerox, but Brooks’s article tells an important part of the company’s early story. He shows how it was built on original, outside-the-box thinking, which makes it all the more surprising that as Xerox matured, it would miss out on unconventional ideas developed by its own researchers.

Download a free chapter

PDF for PC, Mac and Tablet

PDF for e-reader

Buy the full e-book at Amazon.com

Brooks was also a masterful storyteller. He could craft a page-turner like “The Last Great Corner,” about the man who founded the Piggly Wiggly grocery chain and his attempt to foil investors intent on shorting his company’s stock. I couldn’t wait to see how things turned out for him. (Here’s a spoiler: Not well.) Other times you can almost hear Brooks chuckling as he tells some absurd story. There’s a passage in “The Fate of the Edsel” in which a PR man for Ford organizes a fashion show for the wives of newspaper reporters. The host of the fashion show turns out to be a female impersonator, which might seem edgy today but would have been scandalous for a major American corporation in 1957. Brooks notes that the reporters’ wives “were able to give their husbands an extra paragraph or two for their stories.”

Brooks’s work is a great reminder that the rules for running a strong business and creating value haven’t changed. For one thing, there’s an essential human factor in every business endeavor. It doesn’t matter if you have a perfect product, production plan, and marketing pitch; you’ll still need the right people to lead and implement those plans.

That is a lesson you learn quickly in business, and I’ve been reminded of it at every step of my career, first at Microsoft and now at the foundation. Which people are you going to back? Do their roles fit their abilities? Do they have both the IQ and EQ to succeed? Warren is famous for this approach at Berkshire Hathaway, where he buys great businesses run by wonderful managers and then gets out of the way.

Business Adventures is as much about the strengths and weaknesses of leaders in challenging circumstances as it is about the particulars of one business or another. In that sense, it is still relevant not despite its age but because of it. John Brooks’s work is really about human nature, which is why it has stood the test of time.

Melinda picked up this novel earlier this year, and she loved it so much that she kept stopping to read passages out loud to me. I started it myself at 11 p.m. one Saturday and stayed up with it until 3 the next morning. Anyone who occasionally gets overly logical will identify with the hero, a genetics professor with Asperger’s Syndrome who goes looking for a wife. (Melinda thought I would appreciate the parts where he’s a little too obsessed with optimizing his schedule. She was right.) It’s an extraordinarily clever, funny, and moving book about being comfortable with who you are and what you’re good at. I’m sending copies to several friends and hope to re-read it later this year. This is one of the most profound novels I’ve read in a long time.

Business Adventures, by John Brooks, is the best business book I’ve ever read. Unfortunately, it is not easy to find. The book went out of print in the early 1970s. The original publisher is out of business, and Brooks died in 1993. But his family kindly agreed to provide one chapter as a free e-book, which you can download below.

“Xerox Xerox Xerox Xerox,” which originally appeared in the April 1, 1967 issue of The New Yorker, demonstrates all the strengths that made Brooks such a special writer: his intellect, his ability to see the big picture, and his sense of humor. I hope you’ll check it out.

Download a free chapter

PDF for PC, Mac and Tablet

PDF for e-reader

Buy the full e-book at Amazon.com

In addition to this free chapter, the full version of Business Adventures was recently released by a new publisher as an e-book. You can buy it at many retailers’ websites.

As I wrote in my full review, Warren Buffett first recommended this book to me in 1991, shortly after we first met. He loaned me his copy and we had a lot of fun talking about what we had learned from it. So it’s great to be able to share this neglected classic with the wider audience that it deserves.

One of the architects of the Affordable Care Act (a.k.a. Obamacare) makes the case for why the U.S. health care system needed reform and how Obamacare sets out to fix the problems. Although he was deeply involved in its creation, Ezekiel J. Emanuel is good about making it clear when he’s educating you about the history of health care and when he’s advocating for his ideas. 

In Reinventing American Health Care: How the Affordable Care Act Will Improve Our Terribly Complex, Blatantly Unjust, Outrageously Expensive, Grossly Inefficient, Error Prone System, he calls out a few things he disagreed with in Obamacare, like the creation of a separate health-insurance exchange for small businesses. And unlike a lot of experts, he’s willing to make predictions about how health care will change in the coming years. 

Some day we’ll be able to look back and see whether he was right. The facts and history that Emanuel lays out would be useful to anyone involved in the debate over health care, no matter what their point of view is.

The car I drive to work is made of around 2,600 pounds of steel, 800 pounds of plastic, and 400 pounds of light metal alloys. The trip from my house to the office is roughly four miles long, all surface streets, which means I travel over some 15,000 tons of concrete each morning.

Once I’m at the office, I usually open a can of Diet Coke. Over the course of the day I might drink three or four. All those cans also add up to something like 35 pounds of aluminum a year.

I got to thinking about all this after reading Making the Modern World: Materials and Dematerialization, by my favorite author, the historian Vaclav Smil. Not only did I learn some mind-blowing facts, but I also gained a new appreciation for all the materials that make modern life possible.

This isn’t just idle curiosity. It might seem mundane, but the issue of materials—how much we use and how much we need—is key to helping the world’s poorest people improve their lives. Think of the amazing increase in quality of life that we saw in the United States and other rich countries in the past 100 years. We want most of that miracle to take place for all of humanity over the next 50 years. As more people join the global middle class, they will need affordable clean energy. They will want to eat more meat. And they will need more materials: steel to make cars and refrigerators; concrete for roads and runways; copper wiring for telecommunications.

I had already read Smil’s books on energy and diet. Smil says at the start of Making the Modern World that he won’t spend much time on those topics (which means climate change doesn’t come up much). Instead he’s interested in the materials we use to meet the demands of modern life. Can we make enough steel for all those cars and enough concrete for all those roads? What are the risks if we do? In other words, can we bring billions of people out of poverty without destroying the environment?

Smil excels at answering big questions like these. Although he doesn’t make many predictions, he does something that’s even more valuable: He explains the past. He helps you understand how we got where we are, which tells you something about where we’re going. I study Smil’s histories so I can understand the future.

He argues that the most important man-made material is concrete, both in terms of the amount we produce each year and the total mass we’ve laid down. Concrete is the foundation (literally) for the massive expansion of urban areas of the past several decades, which has been a big factor in cutting the rate of extreme poverty in half since 1990. In 1950, the world made roughly as much steel as cement (a key ingredient in concrete); by 2010, steel production had grown by a factor of 8, but cement had gone up by a factor of 25. This animated GIF shows the dramatic transformation of Shanghai since 1987. Most of what you’re seeing in that picture is concrete, steel, and glass.

You can also see the importance of concrete in the graphic below, which illustrates what Smil calls the most staggering statistic in his book:

One material that I have a personal interest in is paper (which comes in a distant third in terms of annual production, behind cement and steel). I’ve been saying for many years that widespread computing would eliminate the need for paper, so I was curious to see where Smil thinks things stand. According to his research, paper production started dropping in the United States in the mid-90s and in Japan a few years later. But global consumption is still going up, driven by China and other growing Asian countries. In 2011 China alone accounted for just over 25 percent of the global paper supply. It was also the world’s top importer of waste paper for recycling. The odds are decent that the junk mail you tossed into the recycling bin last night is headed for China.

I still think we’ll see a paperless office someday, given the downward trend in the United States and elsewhere and the rise of ubiquitous computing. But Smil reminded me that the death of paper is a long way off. This is another reason I like to read him—he keeps my optimism from getting out of hand.

After reviewing the trends, Smil introduces a surprising and counterintuitive idea he calls relative dematerialization. As innovation lets us make a given product more efficiently, with fewer materials or energy, prices go down and consumption goes up. Someone figures out how to make cell phones with less metal, which makes them cheaper, which makes them more widespread. Less metal per phone, but more phones, so more metal overall. “Less,” he writes, “has thus been an enabling agent of more.”

Here’s how the idea applies to soda cans:

What does all this tell us about the future?

First, the good news: Thanks to technical advances, we can make major industrial products like steel and cement more efficiently than ever. On average, making a ton of steel today takes a third as much energy as it did in 1950, and produces 10 percent less carbon.

On the other hand—getting back to relative dematerialization—there’s no end in sight to the rising demand for more materials. Even though the richest countries are leveling off, many other countries are catching up. Smil points out that if the poorest 80 percent of the planet reaches a living standard that’s just a third of what people in rich countries enjoy, the world should expect to continue using more materials for generations to come.

So if consumption won’t level off anytime soon, are we doomed to run out of the stuff that makes modern life possible? As usual, Smil refuses to provide pat predictions. He does say we shouldn’t lose sleep worrying about running out in the next 50 years. Beyond that, there are a lot of variables, but we might need to limit the use of some materials or do a better job with recycling. Smil nods to several innovations that could help avoid future shortages, such as new materials that could cut our need for cement by 65 percent.

I agree with Smil that humans have an amazing capacity for finding ways around scarcity by using materials more efficiently, recycling them, or finding substitutes. The big concern isn’t so much whether we will run out of anything—it’s the impact that extracting and using these materials is having on the planet. For example, the cement industry now accounts for about 5 percent of all carbon-dioxide emissions. That’s one reason I think that developing affordable energy that produces zero carbon is one of the most important things we can do to lift people out of poverty.

I’m also surprised that the oceans get so little attention compared with other environmental problems, and I think they deserve more. They are being overfished and the waters are turning more acidic, killing off coral reefs around the world. Smil cites estimates that at least 6.4 million tons of plastic litter enter the oceans every year. We may have already done irreparable damage to these precious resources.

Above all, I love to read Smil because he resists hype. He’s an original thinker who never gives simple answers to complex questions. He gives me a lot to think about on my drive to work, before my first Diet Coke of the day.

Bono calls the economist Jeffrey Sachs “the squeaky wheel that roars.” To me, Sachs is the Bono of economics—a guy with impressive intelligence, passion, and powers of persuasion who is devoting his gifts to speaking up for the poorest people on the planet. So it was no surprise to me that a journalist would find Sachs to be a compelling central character for a book—and a good way to draw readers into the potentially dry subject of international development.

In The Idealist, Vanity Fair writer Nina Munk draws a nuanced portrait of Sachs and his Millennium Villages Project (MVP)—a $120 million demonstration project intended to show the world that it’s possible to lift African villages out of poverty through a massive infusion of targeted assistance. It would have been easy, and perhaps more marketable, for Munk to draw a caricature, overly accentuating Sachs’s negative qualities at the expense of his great gifts. But she doesn’t. Munk spent six years researching the book, getting to know Sachs well and living for extended periods in two of the 15 Millennium Villages. She clearly appreciates the importance and difficulty of what Sachs and his team are attempting to do.

Unlike most books about international development, Munk’s book is very readable and not long (260 pages). I’ve told everyone at our foundation that I think it is worth taking the time to read it. It’s a valuable—and, at times, heartbreaking—cautionary tale. While some of the Millennium Villages have succeeded in helping families improve their health and incomes, Munk concludes that the two villages she spent the most time studying­—Dertu, Kenya and Ruhiira, Uganda—have so far not lived up to Sachs’s vision.

Sachs did come to the foundation, asking us to support the Millennium Villages. His pitch was intriguing. He was picking a small handful of villages to be the focus of intense interventions in health, education, and agriculture—all at once. His hypothesis was that these interventions would be so synergistic that they would start a virtuous upward cycle and lift the villages out of poverty for good. He felt that if you focus just on fertilizer without also addressing health, or if you just go in and provide vaccinations without doing anything to help improve education, then progress won’t be sustained without an endless supply of aid.

My colleagues and I had a number of concerns about Sachs’s approach. We questioned his assumptions about how quickly the gains would materialize, what would happen when the MVP funding was phased out, how much governments would contribute to offset the high per-person costs, and how feasible it was to measure progress (given the likelihood that people from the surrounding area would stream into their villages once the MVP aid started flowing). So we decided not to invest in the MVP directly. Instead we funded his interdisciplinary work at Columbia University’s Earth Institute, because we felt it was invaluable to have him focused on the needs of poor countries.

Based on what Munk reports about the MVP, I’m not about to throw stones. We have many projects of our own that have come up short. It’s hard to deliver effective solutions, even when you plan for every potential contingency and unintended consequence. There is a natural tendency in almost any kind of investment—business, philanthropic, or otherwise—to double down in the face of difficulty. I’ve done it, and I think most other people have too. 

So what went wrong? For one thing, the villages that Sachs picked experienced all kinds of problems—from drought to political unrest. For another, the MVP began with an idealistic “Field of Dreams” approach. MVP leaders encouraged farmers to switch to a series of new crops that were in demand in richer countries—and experts on the ground did a good job of helping farmers to produce good crop yields by using fertilizer, irrigation, and better seeds. But the MVP didn’t simultaneously invest in developing markets for these crops. According to Munk, “Pineapple couldn’t be exported after all, because the cost of transport was far too high. There was no market for ginger, apparently. And despite some early interest from buyers in Japan, no one wanted banana flour.” The farmers grew the crops, but the buyers didn’t come.

Of course, Sachs knows that it’s critical to understand market dynamics; he’s one of the world’s smartest economists. But in the villages Munk profiled, Sachs seems to be wearing blinders.

Warren Buffett likes to say, “The rear-view mirror is always clearer than the windshield.” Through that rear-view mirror, we can see that the project didn’t have an economic model that could sustain successes once the MVP dollars ran out. All of the interventions involved—health, agriculture, infrastructure, education, and business seed money—make sense if carried out carefully, over time. But I am surprised by how little Sachs dug into country budgets and that he didn’t work to convince governments to commit to additional taxation to fund more of these interventions domestically. Given his background, he surely excels in that area.

Through the rear-view mirror, we can also see that many of Sachs’s ideas have proved to be exactly right. Munk details his 2007 fight with international aid donors who were refusing to distribute insecticide-treated bed nets for free because they favored a market-based approach where people would pay a small amount for each net. To put it mildly, Sachs didn’t make any friends in the process of advancing his case for free bed nets. Through increasingly ruthless tirades, he wound up alienating potential allies who want to defeat malaria just as badly as he does. But history will show that Sachs was absolutely right. Since then, we’ve seen that the free model has allowed for much broader distribution of bed nets—and much greater reductions in malaria—than market models.

In the end, I hope poverty fighters will not let what they read in this book stop them from investing and taking risks. In the world of venture capital, a success rate of 30 percent is considered a great track record. In the world of international development, critics hold up every misstep as proof that aid is like throwing money down a rat hole. When you’re trying to do something as hard as fighting poverty and disease, you will never achieve anything meaningful if you’re afraid to make mistakes.

I greatly admire Sachs for putting his ideas and reputation on the line. After all, he could have a good life doing nothing more than teaching two classes a semester and pumping out armchair advice in academic journals. But that’s not his style. He rolls up his sleeves. He puts his theories into action. He drives himself as hard as anyone I know.

I have no doubt that Sachs, like all relentless thinkers and doers, will come back with stronger ideas and approaches. Sachs will always be a squeaky wheel that roars. And the world will be a better place for it.

The other day I spoke at an employee event at the Gates Foundation. We do these “unplugged” sessions periodically. I open with a few remarks and then spend an hour or so taking questions from the team. I see our senior staff quite often, but these sessions are a great way to connect with the larger group.

I told the staff: If you want to learn about why human welfare overall has gone up so much over time, you should read The Great Escape: Health, Wealth, and the Origins of Inequality, by Angus Deaton, a distinguished Princeton economist who has spent decades studying measures of global poverty. It’s quite accessible, and the first six chapters teach you a lot about economics. But the seventh and final chapter takes a strange turn: Deaton launches a sudden attack on foreign aid. It’s by far the weakest part of the book; if this is the only thing you read about aid, you will come away very confused about what aid does for people.

Deaton’s parting shots came as a surprise to me, because it’s clear from the rest of the book that we see the world in similar ways. His first paragraph is dead-on: “Life is better now than at almost any time in history. More people are richer and fewer people live in dire poverty. Lives are longer and parents no longer routinely watch a quarter of their children die.” (I would have cut “almost” from the first sentence, but otherwise I could not agree more.) Picking up on the title of the old Steve McQueen movie, he calls this improvement in human welfare the Great Escape.

I have long believed that innovation is a key to improving human lives. Advances in biology lead to lifesaving vaccines and drugs. Discoveries in computer science lead to new software and hardware that connect people in powerful new ways. Deaton does a good job of documenting how innovations helped spark the Great Escape.

But the Great Escape, Deaton says, “is far from complete.” Innovations reach only those who can afford to pay for them. And that has led to great inequality. The rest of the book examines where this inequality comes from, whether it matters, and what if anything can be done about it.

One of Deaton’s most helpful passages explains how you measure human welfare in the first place. He argues that there’s no single good measure, but health and GDP are the best two that we have. You probably have heard about gross domestic product, or GDP, but you might not know how it’s calculated, how it’s different from gross national product, or why on its own GDP is not a great measure of the quality of people’s lives. Deaton provides a lucid and succinct explanation.

He is also humble about the limits of economic analysis. In this entertaining passage, he goes after economists who make unfounded assertions about economic growth:

Economists, international organizations, and other commentators are fond of taking a few high-growth countries and looking for some common feature or policy, which is then held up as the “key to growth”—at least until it fails to open the door to growth somewhere else. The same goes for attempts to look at countries that have done badly (the “bottom billion”) and divine the causes of their failure. These attempts are much like trying to figure out the common characteristics of people who bet on the zero just before it came up on a roulette wheel; they do little but disguise our fundamental ignorance.

Unfortunately, this humility goes out the window once Deaton starts criticizing foreign aid. After examining the history of GDP in countries that get aid, he concludes that aid doesn’t cause growth. In fact he makes an even stronger claim—that aid keeps poor countries from growing—and says the most compassionate thing we can do is to stop giving it.

In other words, in one chapter, Deaton dismisses people who think they know why countries fail to grow. In the next, he asserts that countries fail to grow because of aid.

Deaton makes another common mistake among aid critics: He talks about foreign aid as if it’s one homogeneous lump. He judges money for buying vaccines by the same standard as money for buying military hardware.

It seems obvious that programs should be measured against their original purpose. Did the program have a good goal, and did it achieve the goal? Instead, Deaton and other aid critics look at, say, aid that was designed to prop up some American industry, see that it didn’t raise GDP in poor countries, and conclude that aid must be a failure.

That’s a shame, because programs that are actually designed to improve human welfare—especially health and agriculture—are some of the best spending that a rich country can do on behalf of the poor. They help the poor benefit from the very innovations Deaton writes about so glowingly. And their success rate is at least as good as the track record of venture capital firms. No one looks around Silicon Valley and says, “Look at all the startups that go under! Venture capital is such a waste. Let’s shut it down.” Why would you say that about aid?

Deaton spends a lot of time on the concern that foreign aid undermines the connection between governments and their people. The idea is that leaders of countries that get a lot of aid will worry more about what their donors think than what their citizens think.

This argument always strikes me as strange. For one thing, many countries—Botswana, Morocco, Brazil, Mexico, Chile, Costa Rica, Peru, Thailand, Mauritius, Singapore, and Malaysia, to name a few—have grown so much that they receive hardly any aid today. Deaton doesn’t cite any evidence that aid undermined their institutions or democratic values. And his over-emphasis on institutions leads him to make sweeping statements like “drugs and vaccines save lives, but the pernicious effects are always there.” I have to wonder what pernicious effects came from eradicating smallpox, and whether these effects could be worse than a disease that killed millions of people every year for centuries.

Deaton is right to point out some problems with aid. For example, too much goes to upper-middle-income countries rather than focusing on the poorest people. More aid can be directed to specific goals like vaccination. And aid shouldn’t be used to replace domestic funding. But I wish he had spent more time than he does exploring better ways to give aid. Most importantly, we need to help develop a system that identifies the goals of every type of aid and makes it easier to measure which approaches work best in various situations.

If you read The Great Escape—and there’s a lot to recommend in it—you should also read something else to balance out Deaton’s negative views on aid. I’ve highlighted a few recommendations in the Other Reviews box at the bottom of this page. They’ll give you a clearer sense of what’s working, what isn’t, and how we can make our efforts even more effective in the years ahead.

The year 1981 was a big one in my business life. It was the year Paul Allen and I incorporated Microsoft in our home state of Washington.

As it turns out, 1981 also had big implications for my current work in health, development, and the environment. Right when Paul and I were pulling all-nighters to get ready for the release of the MS-DOS operating system for the brand new IBM-PC, two rival professors with radically divergent perspectives were sealing a bet that the Chronicle of Higher Education called “the scholarly wager of the decade.”

This bet is the subject of Yale history professor Paul Sabin’s new book. The Bet: Paul Ehrlich, Julian Simon, and Our Gamble over Earth’s Future provides surprising insights for anyone involved in addressing the world’s “wicked problems.” Most of all, it gave me new perspective on why so many big challenges get bogged down in political battles rather than being focused on problem-solving.

So what was the bet? University of Illinois economist Julian Simon challenged Stanford biologist Paul Ehrlich to put his money where his mouth was and wager up to $1,000 on whether the prices of five different metals would rise or fall over the next decade. Ehrlich and Simon saw the price of metals as a proxy for whether the world was hurtling toward apocalyptic scarcity (Ehrlich’s position) or was on the verge of creating greater abundance (Simon’s).

Ehrlich was the country’s, and perhaps the world’s, most prominent environmental Cassandra. He argued in books, articles, lectures, and popular television programs that a worldwide population explosion threatened humanity with “the most colossal catastrophe in history” and would result in hundreds of millions of deaths from starvation and dire shortages not just of food but all types of raw materials.

Simon, who passed away in 1998, was a population optimist. A disciple of conservative University of Chicago economist Milton Friedman, Simon believed the doomsayers’ models gave little or no credit to the power of efficient markets and innovative minds for developing substitutes for scarce resources and managing out of crises. He went so far as to claim that population growth should “thrill rather than frighten us.”

At the time of the bet, Simon was a relatively unknown scholar who loved using the eminent Ehrlich as a foil. In public, Ehrlich didn’t even acknowledge Simon by name. Nonetheless, Ehrlich rose to Simon’s bait. “It seemed a small price to pay to silence Julian Simon for ten years,” in the words of Sabin.

Who won the bet? Simon. Definitively. Even as the world population grew from 4.5 to 5.3 billion in the 1980s, the five minerals that were included in the bet—chromium, copper, nickel, tin, and tungsten—collectively dropped in price by almost half. Ehrlich begrudgingly made good on the bet. But to this day he still does not concede that his predictions of Mathusian horrors have been off the mark. Similarly, he does not acknowledge that the discipline of economics has anything of value to contribute to discussions of population or the environment.

Even though I had gone back in recent years to read Ehrlich’s Population Bomb (1968) and the Club of Rome’s intellectually aligned book Limits to Growth (1972), The BetLimits to Growth was a stark reminder to me of how apocalyptic a big part of the environmental movement has been. Ehrlich claimed to have science on his side in all of his predictions, including how many people the Earth can feed. He stated as scientific fact that U.S. lifestyles were unsustainable, calling developed countries “overdeveloped countries.” claimed the credibility of computer modeling to justify its predictions of apocalypse.

Simon was equally extreme in his rhetoric. He was as reflexively dismissive of the discipline of ecology as Ehrlich was of economics. And his sound bites provided great fodder for Ronald Reagan and other conservative politicians eager to push back on the pronouncements of environmental scientists. But history generally has been kinder to his predictions than those of Ehrlich.

We know now that Ehrlich was extremely wrong and that following his scientific certainties would have been terrible for the poor. He floated the concept of mandatory sterilizations. He pushed aggressively for draconian immigration policies that, if enacted, would have kept out much of the foreign talent that came into the U.S. over the past three decades and added greatly to the U.S. economy. Ehrlich and his fellow scientists criticized the Green Revolution’s agricultural innovations because, in his view, “we [will] have an even bigger population when the crash comes.”

On population, Ehrlich ignored the evidence that countries that developed economically dropped their birth rate. (The current view is that population will rise only modestly after hitting a bit over 9 billion by 2050.) Granted, population growth is a huge issue in some poor countries, where it creates locally some of the instability and scarcity that Ehrlich foresaw for the entire world. But fortunately, there is strong evidence that if we continue to produce innovative reproductive health tools and make them available to women who want them, and we keep pushing forward on economic growth, there will be fewer and fewer of these places in the decades ahead.

Matt Ridley’s book The Rational Optimist (2010) is probably the best statement today of the Simon case, and Ridley was more careful than Simon was in his claims. Even though I agree with a lot of the book, it too easily dismisses the need to address problems of the poorest, climate change, and the oceans.

The recent Economist special report on biodiversity makes a strong case that economic growth allows us to make environmental concerns a priority. It contrasts the environmental record of the rich countries with that of poor countries to say that economic growth is the best hope for environment protection. All of this suggests to me that we should be wary of broad attacks on economic growth. (The authors of the special report admit that it’s not focused on climate change and mostly leaves aside the mismanagement of the oceans, which is tragic problem that deserves more focus.)

I recommend The Bet to anyone wanting to understand the history of the divisive discussions we have today, especially the stalemate over climate change. Sabin makes a strong case that Ehrlich’s brand of science made it easy for conservative critics to caricature environmentalists as doom merchants and fear mongers who peddle dubious science as a means of advancing their big-government agenda.

And Simon is far from blameless. “Julian Simon and other critics of environmentalism … have taken far too much comfort from extravagant and flawed predictions of scarcity and doom,” writes Sabin. “By focusing solely and relentlessly on positive trends, Julian Simon made it more difficult to solve environmental problems.”

It’s a shame that extreme views get more attention and more of a following than nuanced views. We see this dynamic clearly when the Intergovernmental Panel on Climate Change does its best to be clear and impartial in conveying what is known on the key issues, but both liberals and conservatives make it hard for the public to understand the panel’s nuanced conclusions.

I wish there more people who took the middle ground and who were as prominent as Simon or Ehrlich. So here’s my question to you: What’s the best way to encourage scholars to combine the best insights from multiple disciplines? How can we elevate the status of scientists and spokespeople who refuse the lure of extremism and absolutism? 

Last week I mentioned I’d be reviewing Jared Diamond’s latest book and invited you to share your thoughts on the book. I wasn’t sure what the response would be. It wasn’t exactly light beach reading, and ten days isn’t much time to find and finish a 460-page book. But I was pleased by how many people responded. Thanks to everyone who weighed in.

A number of commenters hadn’t heard of Diamond before. But I was encouraged by this post from Addison Staples: “I was actually lucky enough as a teenager to be required to read Guns, Germs, and Steel as preparatory reading for AP World History. I was blown away, probably the only book I was ever forced to read in school that absolutely engaged and enlightened me.” That’s great. Every student deserves to be inspired like that.

As for the new book, Andrea wrote that it “is a very good read, in my opinion, but nothing more. It lacks the great enlightenment of the other books” that Diamond has written. I had a similar reaction.

Diamond starts with the premise that human beings were hunter-gatherers for millions of years, and only settled down when we began farming about 10,000 years ago. So most of our genetic selection has been done in a hunter-gatherer environment. He argues that we can learn a lot by studying hunter-gatherer societies in places like New Guinea, where he has spent much of his career. (He uses the term New Guinea to refer to the island that is divided between Indonesia and Papua New Guinea.)

He describes several areas in particular, like raising children, dealing with the elderly, and eating well. He doesn’t romanticize these societies, as I thought he might, or make some grand pronouncement that they all do these things better than we do. He just wants to find the best practices and share them.

Unfortunately, I didn’t find much deep wisdom in the lessons that Diamond documents. But I found the book fascinating anyway.

In part that’s because Diamond has such good anecdotes. There’s one involving a New Guinean nomad who finds a small tree coming out of the ground and becomes convinced it’s a sign of danger. As I read the story, I was sure something bad was about to happen. Diamond eventually concludes that the man was right, but not for the reasons I expected.

At a broader level, The World Until Yesterday made me think about how we have had to overcome some deeply ingrained behaviors in order to develop a modern, interconnected society. As Diamond explains, in a hunter-gatherer society, you trust people in your own group because you know for the most part they share your interests. But when you encounter strangers, you have to assume they’re dangerous. You have a strong incentive to do this: If you don’t, and you turn out to be wrong, they could end up killing you or stealing your food.

Things are different in a modern society. You probably passed by a lot of strangers today without having to figure out whether they might try to kill you or take your lunch. That is a very primal fear we have overcome in order to live in large cities.

Consider how important this has been for global trade and international travel. How many strangers have to do business with each other every day to make the global economy work? Although globalization has been driven by inventions like the jet engine and the standardized shipping container, it wouldn’t be happening unless we were also able to overcome a natural suspicion of strangers. It is another reminder of humans’ amazing ability to adapt.

How did this shift happen? Diamond writes a bit about how on a local level (like for tribes in New Guinea) it’s driven by the need to share scarce resources, such as food. But it’s not really his main point. One book that gets deeper into these questions is The Rational Optimist: How Prosperity Evolves, by Matt Ridley. Ridley focuses on trade more broadly and what it took to overcome these very basic barriers to working with strangers. I’d recommend it to anyone who is interested in this area.

I did appreciate a few of the other observations in Diamond’s book. He is convincing in suggesting that we reconsider how much we isolate the elderly. It is a waste to have people with experience and the free time to share it, and lots of young people who would benefit from it, but no way to connect them. This is an area where I think communications technology could still make a big difference.

In short, if you’re only going to read one Jared Diamond book, make it Guns, Germs, and Steel. But if you have a particular interest in what life is like for hunter-gatherers, The World Until Tomorrow is a good choice.

Finally, a number of commenters suggested similar books to Diamond’s. Nobuo Ikeda mentioned The Better Angels of Our Nature, which is one of my favorite books ever and one I think everyone should read. You can find my review here. Scott and others recommended Why Nations Fail, which I disagreed with pretty strongly and reviewed here.

Thanks again to everyone who participated in this experiment. I’ll be moving on to some of the other titles on my summer reading list and will post more reviews when I can.

I’m a big fan of the author Jared Diamond. His book Guns, Germs, and Steel had a huge impact on how I understand world history. I also enjoyed his latest, The World Until Yesterday, which I reviewed here. Professor Diamond was kind enough to respond to a few of my comments about the book.

BILL GATES: Reading The World Until Yesterday, I thought about how it fits in the context of some of your other books. Guns, Germs, and Steel is about why some societies advance faster than others. Collapse is about why some societies fail. This book is more personal, because you draw on a lot of your own experiences. But it also makes a larger argument about what we can learn from traditional societies.

JARED DIAMOND:

This book originated with my idea of writing a somewhat autobiographical book about my experiences in New Guinea for the last 50 years. I found New Guineans fascinating, and I wanted to share with readers my fascination.

When I proposed that to my editor, my editor said, “Jared, people don’t want a little autobiographical book from you. They want a big book summarizing everything about the world for thousands of years.”

So my observations became the frosting on the cake. The cake itself is scholarly studies by people who’ve lived with about 39 traditional societies around the world, and their observations on various aspects of those societies.

I imagine a lot of readers come to this book with stereotypes about traditional societies: either that they are at one with nature and totally peaceful, or that they are ruthless and warlike. In fact before I read the book, I wondered whether you would romanticize the hunter-gatherer lifestyle. But you present quite a nuanced view.

For much of the past several centuries, people from Europe and Americans have viewed traditional societies, including our Native American societies, as groups who should be gotten out of the way as quickly as possible or dragged into the modern age whether they like it or not.

The opposite view idealizes traditional people as tree-hugging, peaceful environmentalists who don’t have war and are not subject to all the evil things that began with our state governments.

Both of those extremes, of course, are unrealistic because people are people.

In some cases what goes on in traditional society is pretty terrible and our reaction is, “Thank God we’re through with that,” such as uninterrupted tribal warfare. In other cases what goes on in traditional societies most of us would admire, and many of us can adopt it ourselves individually, such as the way they bring up children.

You write about the violence in traditional societies. It made me think of Steven Pinker’s The Better Angels of Our Nature, which shows how and why the world has become a less violent place over the centuries. One factor is the growth of centralized governments that have a monopoly on punishing people. You’ve seen examples where police come in to an area for the first time. As soon as they make it clear that the first guy to take revenge will go to prison, the levels of violence drop very quickly.

During my first trip to New Guinea in 1964, I was working at an Australian post in an area where there were 20,000 New Guineans. There was one Australian patrol officer, and there was one British schoolteacher, and there were four native police. The patrol officer and the four native police had guns. There were 20,000 New Guineans without guns but with bow and arrow.

The New Guineans had been fighting with each other until a few years before that. So the Australians would come in, they’d make examples of New Guineans who did fight by arresting them. The Australian patrol eventually marched away, leaving this one patrol officer and four policemen and their five guns.

It’s perfectly obvious that if those 20,000 New Guineans had wanted to resume fighting, it would have been the simplest thing in the world to kill or ambush the patrol officer and the four policemen. It’s not the mighty military power of those five guns that are keeping the 20,000 people from fighting.

The reason is that in traditional New Guinea there was not a higher authority that could order an end to warfare. And so New Guineans were caught up in these almost endless cycles of revenge and counter revenge. New Guineans knew better than I or any of my readers what they suffered from warfare.

I should add that it’s not the case that all traditional societies are universally violent. It appears that hunter-gatherers living in low population density are less violent than settled, sedentary farming societies because the farming societies can have borders that they can police. It’s also the case that societies that don’t have anything valuable worth defending are less likely to fight.

One of the key points I got from the book is the way our genes are shaped by our past in hunter-gatherer societies, whether it’s goal-seeking, procreation, or other behaviors. It seems clear that some of that is hard-wired. You can take humans and put them into virtually any situation and they will behave in certain ways.

The human evolutionary line has been a separate evolutionary line that diverged from the evolutionary line of chimpanzees 6 million years ago. It’s only about 10,500 years ago that agriculture emerged. Everybody was living in bands and tribes until the first chiefdom arose only about 7,500 years ago.

So we’ve evolved under traditional conditions for a very long time, and it’s only within the last 10,000 years that the stuff that we take for granted, like state governments, has arrived, and that hasn’t given much time for genetic change.

Now, I have to add there has been some genetic change. We’ve gotten genetic change in some populations that allows us to drink milk as adults, whereas there wasn’t any human on the face of the earth who drank milk as an adult before probably about 8,000 years ago.

You have a section in the book on what you call constructive paranoia. It’s interesting how a lot of people worry a lot about certain bad things happening to them that are very remote possibilities, and they don’t think much at all about everyday dangers that can add up to significant risk. You talk about how New Guineans are smarter about calculating risk and how you apply that approach in your own life.

I personally have gotten much more careful about taking showers. I realize people say, “Jared, that’s ridiculous. Your chances of falling in the shower are one in one thousand.” Yes, they may be one in one thousand, but then do the math.  I’m 75. Statistically I’m expected to live to 90. If I take a shower every day, that’s 5,475 showers. If I reduce my risk to one in a thousand, that means I’m going to kill myself five and a half times before I reach my life expectancy at age 90.

And so I worry that taking a shower is the most dangerous thing I’ll do today. I also stood on a stepladder, the second most dangerous thing that I’ll do today.

Anyone interested in politics may be attracted to Nate Silver’s The Signal and the Noise: Why So Many Predictions Fail – but Some Don’t. Silver got a lot of attention in 2012 for predicting—accurately, as it turned out—the results of the U.S. presidential election. This book actually came out before the election, though, and it’s about predictions in many domains besides politics. Silver knows a lot about baseball, and I especially liked his explanation of hold’em poker. A few pages where he talks about how early computers supposedly made everything less efficient are utter nonsense. I wish he had gone into more depth on some things, like why it is that voters are increasingly polarized.

In his book, The Better Angels of Our Nature, Steven Pinker shows with data and charts how violence is declining. Here’s a look at some of the data from the book.

Between the late Middle Ages and the 20th century, European countries saw a tenfold-to-fiftyfold decline in their rates of homicide.

While the 20th century certainly had more violent deaths than earlier ones, it also had more people. World War II was certainly the worst thing that happened in human history in terms of absolute number of people killed. It’s not clear whether it was the worst in terms of the proportion of the population that was killed, because there were atrocities in previous generations that proportionately were comparable – the European Wars of Religion, the Mongol Invasions, to say nothing of tribal warfare that could kill a much larger percentage of the population than died in World War II.

The rates of violence did a U-turn in the wrong direction in the 1960s. After centuries of violence going down, in the 1960s it went back up. The rebounding of violence in the 1960s defied every expectation. The decade was a time of unprecedented economic growth, nearly full employment, historical racial progress, and the blossoming of government social programs.

Use of the terms civil rights, women’s rights, children’s rights, gay rights, and animal rights in English-language books, 1948-2000. These staggered rises tell a story. Each of the movements took note of the success of its predecessors and adopted some of the tactics, rhetoric, and most significantly, moral rationale. The Rights Revolutions have brought us measurable and substantial declines in many categories of violence.

Violence in many ways has plunged over the course of history. The decline of violent behavior has been paralleled by a decline in attitudes that tolerate or glorify violence. For centuries, wife-beating was considered a normal part of marriage. In a 1995 survey more than 80 percent of the respondents deemed domestic violence a “very important social and legal issue”, 87 percent believed that intervention is necessary when a man hits his wife even if she is not injured, and 99 percent believe that legal intervention is necessary if a man injures his wife. Surveys that asked the same questions in different decades show striking changes.

From 1990 to 2007 the rate of physical abuse of children fell by half. During this time the rate of sexual abuse, and the incidence of violent crimes against children such as assault, robbery, and rape, also fell by a third to two-thirds. Over the past two decades the lives of children and adolescents improved in just about every way you can measure. They were also less likely to run away, to get pregnant, to get into trouble with the law, and to kill themselves.

Steven Pinker’s book, The Better Angels of Our Nature: Why Violence Has Declined stands out as one of the most important books I’ve ever read. I recently had a chance to sit down with Steven and discuss some of the points from the book in greater detail.

I don’t read a lot of self-help or inspirational books, but even if you never read anything in this genre, Awakening Joy: 10 Steps That Will Put You on the Road to Real Happines is one you should try. It’s about enjoying your life, consciously picking the things that make life more enjoyable and purposefully thinking about them. It shows how to think about spirituality and purpose in your life. The author, James Baraz teaches a very popular course and has an online lecture series on this. Melinda and I actually went to one of his seminars. He’s a very nice guy, and Awakening Joy is very good.

People often ask me what is the best book I’ve read in the last year. Steven Pinker’s The Better Angels of Our Nature: Why Violence Has Declined stands out as one of the most important books I’ve read—not just this year, but ever.

The book is about violence, but paints a remarkable picture that shows the world has evolved over time to be a far less violent place than before. It offers a really fresh perspective on how to achieve positive outcomes in the world.

Pinker presents a tremendous amount of evidence that humans have gradually become much less violent and much more humane. The trend started thousands of years ago and has continued to this day. As I’m someone who’s fairly optimistic in general, the book struck a chord with me and got me to thinking about some of our foundation’s strategies.

I’m a dogged advocate for innovations that have brought us longer life spans, better nutrition and more freedom. But I’m also concerned about the things innovation can’t always change, like how we look at justice and violence. Is there a positive trend there, and if so, what are the lessons? How can we make sure the trend continues? How can we broaden it—and maybe even speed it up?

Many people are surprised to hear that we live in a far less violent time, because you see and read about tons of violence in the news. But Pinker argues convincingly that it’s our awareness and sensitivity to violence that have increased, not violence itself, which is way down.

For example, when archaeologists dig in ancient gravesites, they find that a lot of the people there were clearly murdered, their skulls cracked open before they died. Pinker thoroughly debunks the romantic idea that ancient humans lived in harmony with nature and each other. It’s an overly rosy view of the past and a view that ignores much of the progress we have made.

We began moving away from violence when we first settled down into stable agricultural communities, Pinker writes. After the Enlightenment, governments themselves became less violent, eliminating cruel punishments and other things that infringed on citizen’s rights. And in the two thirds of a century since World War II, nations have become less war-like, especially as the idea of universal human rights has taken hold.

It seems to me that higher rates of violence in some poor countries may have to do with the fact that governance has lagged behind. These are young countries, most of them, and some of their national governments haven’t yet fully established the rule of law and protection for human rights.

Before I picked up The Better Angels of Our Nature, I assumed that most murders were motivated by economic gain. In fact, only about 15 percent of U.S. homicides involve robbery or other economic factors. The perpetrator is usually driven by a sense of injustice or desire for revenge, and he doesn’t trust institutions to mete out punishment.

Also before I read this book, I always thought of honor as a good thing. I can remember my mom impressing on us kids that maintaining your honor by not lying and living right was important. But Pinker makes a case that honor is often a dangerous concept. It used to lead noblemen to kill each other in duels. It can lead to violent feuds, like between the Hatfields and McCoys in the Appalachians in the late 19th century. And some societies still have this notion of honor killing.

Pinker isn’t saying that peace, justice and nonviolence are inevitable. He acknowledges that modern technologies have really expanded how lethal wars can be. Things can go very wrong, but Pinker is saying the arc of history is toward less violence, and we should understand that and tap into it.

His ideas could be very helpful in different countries as a guide to how to build more peaceful societies, which is not just about economics. Some African countries, which still have high murder rates, might find ways to move faster toward  the levels of developed countries. The Better Angels of Our Nature explains some ideas that I think should be widely understood, like the idea that the basis for morality—and the continued decline of violence—lies in empathy, strengthened by rules, codes and laws.

It’s a big book, more than 700 pages, and I wish that the summary chapter was available separately as an article, because many people could benefit from it who might be scared off by a book this long. As a guy who is pretty rigorous about how he spends his time, I think this book is completely worth the time to read it.

I would put “Better Angels” on the same scale as Big History, David Christian’s ambitious project to create a framework for how human history was influenced and shaped by everything around it. 

For me, what’s most important about The Better Angels of Our Nature are its insights into how to help achieve positive outcomes. How can we encourage a less violent, more just society, particularly for the poor? Steven Pinker shows us ways we can make those positive trajectories a little more likely. That’s a contribution, not just to historical scholarship, but to the world.

I’ve visited a lot of urban slums and it’s always difficult to describe to people back home just how bleak they can be. If you want to read an unvarnished, first-hand account of life in one of India’s slums you should pick up Behind the Beautiful Forevers: Life, Death, and Hope in a Mumbai Undercity.

The book was written by Katherine Boo, an award-winning Western journalist who spent three years getting to know the people of Annawadi, a slum of about 3,000 people on the edge of a sewage-filled lake in India’s largest city. Her research alone is a tremendous achievement.

The centerpiece of the story is a family falsely accused of a crime. Their story becomes a way to understand the very tough position people living in slums are in, and the great injustices that happen in a slum. It’s a reminder of how capricious their life can be.  In Annawadi, exploitation and corruption are rampant and you can’t count on fairness or even basic justice if you are one of the world’s poorest.

Ironically, Annawadi survives—for now—amidst gleaming luxury hotels that reflect Mumbai’s status as India’s richest city and its commercial and entertainment capital.

Most of the people come from other parts of India, hoping for a better life. It’s hard for us to imagine that life could be much worse somewhere else. But many poor people are leaving the rural regions on their own because there is at least relative freedom in the slums and also the possibility that you could find something new to do.

Many people in Annawadi survive by scavenging garbage and some by thievery because that’s the only way they can see to make money. Sickness and disease are always present. And life is often unpredictable. Like many slums, the people don’t own the land, so they never know when the government is going to come in and push them out.

So it’s a sad story and it makes you want to help. It reminds us how much more work needs to be done to address the inequities in the world. But it’s also uplifting at times because Boo shows people striving to make a life for themselves, sacrificing for their families, and in their own way, being innovative and entrepreneurial in creating a vibrant local economy.

More broadly, the story of Annawadi reflects the big and growing problem of urban slums. More than 900 million people live in poor, densely-populated areas in developing countries. Over the next several decades, that number is expected to increase to several billion.

Many urban centers are ill-prepared to meet the basic needs of rapidly expanding urban populations today, so it’s sobering to think about it getting worse. It’s difficult for donor organizations and governments to help because there are so many complex local systems involved, such as water, sanitation, policing, the judiciary, and education.

And as Boo shows, even aid organizations can be corrupt, although I do think the two examples she cites can be misleading. I know from first-hand experience that there are thousands of fantastic NGOs and government organizations—in India and elsewhere—working hard and honestly to improve living conditions for the poor.

The foundation works with many of them, including some that are focused specifically on addressing urban poverty. We’re investing in better sanitation and financial services for the poor, which can make a difference in places like Annawadi. We have made improving health a top priority because we believe it is the basic building block for people to make the most of their lives. This includes investing in vaccines and other drugs to tackle diseases that disproportionately affect the poor, and working to improve health care for mothers and children.

All of these things will make an impact in urban slums. But there’s no doubt that urban poverty is a uniquely complex and vexing problem—without a quick or simple solution. As the world population grows by another 2 billion over the next several decades, most of that increase will show up in urban slums. The challenge for our foundation and for other donors is to find ways to collaborate with governments so that aid programs work in tandem with effective delivery of basic services. Otherwise, the suffering and often brutal nature of life will continue for the world’s urban poor. On my trip to India this week, I visited an urban slum in Lucknow, the capital city of the state of Uttar Pradesh, to see what’s working and continue to look for ways we can help improve the lives of the poorest.

After reading the book I had a few questions I wanted to ask Katherine Boo. She has agreed to write a response to my questions which we’ll post here on Gates Notes soon.

I recently read and reviewed That Used to Be Us, a new book on how to strengthen America’s economic competitiveness. I sat down with co-author Thomas Friedman for a probing conversation about the vitally important issues raised by the book.

That Used to Be Us is a fantastic book, and I really encourage people to read it. You’ll definitely like it if you’ve liked Tom Friedman’s column in The New York Times or if you’ve liked his previous books. This one continues his theme of how the world is changing rapidly and in fundamental ways, but this one is a bit different in that it focuses specifically on the challenges that these changes pose for the United States and on how the U.S. should respond.

Friedman is most famous for his bestseller The World is Flat, which is the best articulation of the paradigm shift that’s occurred over the past couple of decades as the world economy has become more globalized and competitive. That Used to Be Us, which Friedman wrote with Michael Mandelbaum, points out that the causes of this paradigm shift—the digital and Internet revolutions—were ideas and technologies that the U.S. pioneered. Now, though, the changes the U.S. helped bring about could be viewed as threatening our unique position in the world.

How the U.S. should deal with global challenges is an interesting and important topic. That Used to Be Us explains these challenges very well and has good suggestions on what the U.S. needs to do. The book has a valuable message and I recommend it, although there are some things I wish the authors had clarified.

The basic message is that other countries, the ones that are now competing with us and kind of scaring us, are not doing anything different from what we did in our past. We have a difficult time responding to them, however, because they’re copying the way we used to be, and meanwhile, we’ve changed. As our society has gotten richer, we’ve become more careful about protecting people’s rights and not harming the environment, for example. It’s good that we care about these things, but it slows us down compared with other countries that are at an earlier stage of development. And we’re not always very good at balancing rights and environmental concerns, on the one hand, with our interest in creating jobs and growing the economy. That’s very hard to do.

Friedman and Mandelbaum are almost saying, “Hey, let's set the clock back to the good old days when there was a bias towards action.” I wish they gave more guidance on how to do that while preserving the good changes we’ve made, including some of our increased focus on rights and the environment. Getting a sense of where the costs of our new approaches outweigh the benefits is hard.

The authors do have one clever suggestion on how to improve the political dialogue: start a third party. Maybe that would change the hyper-partisan atmosphere that prevents compromise and serious discussion of tradeoffs. A couple of decades ago, when partisan divisions were not as strong, some politicians carved out niches for themselves by becoming experts in particular policy areas. They assembled excellent staff and really mastered their subject. That helped them balance tradeoffs and come up with smart, technocratic solutions. Maybe a third party could help encourage that kind of specialization and expertise again.

There’s one question in particular that I wish the book answered more clearly: If other countries are growing and prospering and people in other countries are finding ways out of poverty, is that a bad thing for America? I don’t think so. How would the authors feel if the United States has to give up some of its leadership positions as the world improves overall? To focus attention on actions needed to renew America’s economic vitality, the authors tap into the anxiety that a lot of Americans feel about how well the U.S. is doing compared with other countries. I wish they had made it clear that America can still do well as other countries catch up with us. In fact, their prosperity can help us.

Our unique position relative to other countries largely resulted from the huge mistakes they made in the past. For decades, China ran its economy without market incentives. It stayed very poor. When China opened up in 1979, it began copying good ideas from us. It began pricing goods based on market demand. It began building infrastructure and good universities. It had a lot of catching up to do, but it could move quickly, partly because it didn’t have as much complexity to deal with as we do in the West. Today the Chinese are more like we were in the 1950s. But some Americans feel threatened by that.

I understand why people feel threatened. The economy has been slow to get back on its feet, and jobs are still scarce. Global competition is bringing changes in the economy. People are forced to adapt. Our whole economy needs to adapt. Friedman and Mandelbaum have good ideas for making the U.S. economy stronger and more competitive.

But they never really answer the question: Should 5% of humanity hope the other 95% messes up, just so the 5% can still call themselves exceptional? Isn’t it better for the whole world to become richer and healthier? Doesn’t that create new customers for U.S. goods and services, and make for a more stable world overall?

I sympathize with the anxiety that some Americans feel about the country’s relative position in the world, but I think a lot of it is misplaced. I’ve seen polls showing that a majority of Americans believe their children will live less well than they do. I believe Americans lives will continue to get better. Our current economic challenges aside, do people think the Internet will get slower? That cancer drugs will stop working and that we won’t invent new ones? That cars of the future will have manual brakes and steering? That women will lose their rights? That we’ll go back to watching VHS tapes again?

Anxiety about our place in the world shouldn’t lead us to ignore all the improvements happening as a result of innovation and other progress. We shouldn’t worry so much about whether other countries are catching up with us. Instead we should renew our own economic vitality by doing what we’ve done before: investing for the long term in education, science, infrastructure and stable government.

I’ve flown hundreds of times on airplanes and watched huge container ships enter Seattle’s busy seaport without ever giving much thought to the powerful jet and diesel engines that make the movement of people and cargo by air and sea an everyday occurrence.

Vaclav Smil, on the other hand, has written an entire book about the development and impact of gas turbines and diesel engines. Prime Movers of Globalization is another remarkable book by Smil, a professor at the University of Manitoba and a prolific author who takes an interdisciplinary approach to writing about important topics in the fields of energy, the environment, population, food production, and technical innovation.

As a history buff, I appreciate books that give you a sense of the people behind important inventions and the sweeping impact they have had on society. Often—as in the case of the diesel engine and the gas turbine—incremental advances obscure the profound impact of technology. In Prime Movers, Smil focuses in on a slice of 20^th century technological innovation and shows the phenomenal impact it has had on international trade and travel.

To put the significance of the diesel engine and the gas turbine in perspective, Smil points out that until coal-powered steam engines came along a few hundred years ago, animals and human muscle were the “prime movers” of manufacturing, and wind and sails the prime movers of international travel and trade. The steam engine was an important underpinning of the industrial revolution. But its impact pales in comparison to the diesel engine and the gas turbine.

Today, the diesel engine powers virtually all of the ships that ply the oceans with bulk commodities such as grain and oil, and finished products like cars and consumer electronics. It also is the power source for most freight trains and large trucks. The gas turbine powers more than 18,000 jets that carry millions of people and billions of tons of cargo around the world daily.

Although there were a lot of people tinkering with engines at the turn of the 19^th century, Rudolph Diesel is generally credited with inventing the diesel engine. Diesel didn’t live to see the widespread adoption of his invention. Heavily criticized for his ideas and despairing that they would ever be fully realized, Diesel apparently committed suicide in 1913 by jumping over the side of a steamer ship. Ironically, it soon became obvious that the diesel engine was by far the most efficient, reliable, powerful, and low-maintenance power source for ocean-going vessels, locomotives, large trucks, and heavy-construction equipment.

Building on advances in turbines in the first half of the 20^th century, the U.S. and Germany both began testing gas-powered turbine engines in military aircraft during World War II. That led to the introduction of commercial jet service in the 1950s, with gas turbines quickly replacing propeller-driven engines because of their greater power, efficiency, and performance.

But it was the launch of the first wide-bodied jet—the Boeing 747—in 1970 that really made gas turbines a prime mover. I’ve ridden on 747s many times and have always been impressed—especially during takeoff—by their size. But I didn’t realize what an important role they’ve played in fostering international trade and travel by reducing the cost of flying and making it possible to ship goods around the world overnight.

In fact, Smil says, today’s prime movers have reduced the cost of shipping so much that “distance to the market has been largely eliminated” as a factor in siting manufacturing facilities, sourcing imported materials, or pursing new export markets. Another important development was the containerization of cargo so it can be quickly loaded on and off ships, trains, and trucks. This one advance cut the delivery time of many shipments by more than 95 percent.

Smil includes some fun anecdotes about the people who had a role in these innovations. For instance, the idea of containerized shipping originated with a North Carolina trucker who got tired of waiting all day to have his bales of cotton unloaded at the docks in New Jersey. Why couldn’t they just pick up the trailer attached to his truck and put it on the ship, he wondered?

He also points out several instances of parallel innovation, which is when two or more inventors come up with the same idea at virtually the same time. This is not as uncommon as you might think. Alexander Graham Bell and Elisha Gray each filed patents for the telephone on the same day. In the case of the jet engine, a British inventor and Royal Air Force pilot, Frank Whittle, filed for a patent in 1930. Six years later, a German engineer, Hans Joachim Pabst von Ohain, filed for a patent without knowing of Whittle’s previous work. Ohain’s design was the first to be put to the test in a 1939 flight. But Whittle’s turbojet endured, becoming the foundation on which modern jet engines were built by General Electric, Pratt & Whitney, and Rolls-Royce.

Given my deep concern about climate change and our overuse of fossil fuels, I was happy to see Smil address the issue of energy consumption. Lowering the speed of fast container vessels by 20 percent would reduce fuel consumption by 40 percent—an amount equal to the annual oil consumption in India or Russia. Better hull designs could lower fuel demand by another 10 percent. And although efficiencies in engine design have reduced the fuel consumption of jet engines by 50 percent, Smil believes airlines could further reduce their carbon footprint by improving operational processes. He cites two examples: towing airplanes to the runway rather than having them taxi using their jet engines, and slowing down the speed of aircraft as they approach an airport in order to avoid wasting fuel while they circle their destination.

There are a lot of fascinating historical points and statistics in Smil’s book that make it an interesting read, but what most fascinated me was learning about the incredible impact these two innovations have had on so many aspects of our lives.

I picked up Steven Johnson’s book, Where Good Ideas Come From: The Natural History of Innovation, with a little bit of skepticism. Lots of books have been written about innovation—what it is, the most innovative companies, how you measure it. The subject can seem a little faddish, but Johnson’s book is quite good at giving examples of how you create environments that can encourage good ideas.

Especially for people in business or education, it’s a worthwhile book. It talks about the institutional structures that facilitate good ideas—how you get lots of people thinking about cutting edge problems, how you put people together in a space where different skill sets and influences can come together, how you make the right kinds of materials available but don’t force a conclusion.

Some books about innovation revolve around the idea that a small number of amazingly smart individuals have had Eureka moments, leading to extraordinary breakthroughs that changed the course of civilization.

But Johnson challenges this view, which I liked: “We have a natural tendency to romanticize breakthrough innovations, imagining momentous ideas transcending their surroundings…But ideas are works of bricolage…We take the ideas we’ve inherited or that we’ve stumbled across, and we jigger them together into some new shape.”

The decision to start Microsoft, for example, wasn’t based on a momentous flash of insight. It was based on incremental developments in a nascent personal computing industry, the fact that Paul Allen and I had access to mainframe computers at the high school we attended, and our hunch about what people could do with computers in the future.

At the foundation, our work in global health, development, and education builds on the great ideas that others have developed over the years in a wide range of fields—global health, international development, agriculture, engineering, scientific research, and public policy.

Johnson focuses on the elements of our cultural environment that foster an atmosphere of innovation, and the recurring patterns that often are at play in bringing great ideas to fruition. He believes that urban environments and technology are potent fertilizers of discovery and invention, and that the connections between people and their ideas are the underlying seed beds of innovation.

The author identifies a number of conditions, or patterns, that enable innovation. One is the “adjacent possible,” a theory first articulated by American scientist Stuart Kauffman. It’s the idea that what is achievable today is defined by the various combinations of events and activities that have occurred prior.

For example, in the 1870s, a French doctor, Stephane Tarnier, saw incubators for chicken hatchlings at the Paris Zoo and hired the zoo’s poultry-raiser to build incubator boxes for premature newborns at his hospital. Other hospitals at the time were using devices to keep babies warm, but Tarnier was the first to conduct research showing how incubators significantly reduced the infant mortality rate, leading to their widespread use in Paris and beyond.

Earlier in the 19^th century, a British inventor, Charles Babbage, tinkered with two ideas—a Difference Engine to calculate polynomial functions, and an Analytical Engine, which would have been the world’s first programmable computer. Neither machine was built at the time, but many of the ideas underlying the Difference Engine took hold fairly quickly, leading to the mass production of mechanical calculators. Although the Analytical Engine was a brilliant idea that included many of the key concepts in today’s computers, it was, Johnson suggests, beyond the adjacent possible of the day. Babbage’s design would have required a huge number of mechanical gears and switches, which probably would have made the machine too slow to operate effectively. It took another 100 years for researchers to independently rediscover Babbage’s ideas and apply them using newer technology—vacuum tubes and eventually integrated circuits.

A more recent example of the adjacent possible, Johnson says, is YouTube. If it had been launched 10 years earlier, it would have failed because most people connecting to the Internet were still on slow dial-up connections that could not have handled video sharing. But by the time YouTube launched, many more people had high-speed Internet connections.

Johnson also talks about the importance of “liquid networks” that are flexible enough to facilitate dynamic connections between good ideas, but structured enough to support and hold them. I’m familiar with one of the examples he cites, Building 99 on the Microsoft campus which houses Microsoft Research. To optimize collaboration and creativity, Building 99 was designed so rooms could be easily reconfigured to provide flexible work and meeting spaces. Lots of the walls are covered with whiteboards that allow scientists to gather informally to sketch out ideas whenever inspiration hits. This may not seem revolutionary, but it’s amazing what happens when you open up work spaces in this way versus traditional office cubicles.

A third pattern that Johnson explores is “the slow hunch.” It took Joseph Priestley, an 18^th century scientist, 20 years to conclude that plants create oxygen. (Priestly first had an inkling when, as a child, the spiders he trapped in glass jars died.) The core pieces of Charles Darwin’s theory of natural selection were articulated in his notebooks more than a year before he seemed to fully grasp their significance and published them. I’ve seen this many times at Microsoft and at the foundation. People start with an idea and over time it evolves and becomes clearer.

Serendipity (or what Johnson calls “happy accidents”) accounts for other breakthroughs. He includes dreams, contemplative walks, long showers, and carving out time to read a variety of books and papers that might lead to “serendipitous collisions” of ideas. He mentions the Think Week breaks I’ve taken for many years, where I immerse myself in books and papers that people send me. We expanded who participates in Think Week a few years ago at Microsoft to include the top 50 engineering thinkers. It has definitely led to an exciting exchange of ideas and inspirations that would not otherwise have occurred.

I don’t have space here to cover the other patterns that Johnson talks about, but you can read about them in his book. You can also watch a video of Johnson discussing them at a 2010 TED speech.

All of us have great ideas from time to time. The challenge is how to put more of them into action to help solve the world’s biggest problems. Writers like Johnson remind us that good ideas are most often the result of people building on other’s ideas—either individually or together—and having a fertile environment in which they can prosper.

Stepping into the public square to announce that foreign aid is important and effective can be lonely work.

As someone who has attempted to make that case over the past decade, I can assure you that the world is often eager to hear just the opposite.

Aid money can and does work. It improves people’s lives and makes the world a better and safer place.

Fortunately, an elegant and deeply researched new book has come along to reframe the debate and tip it, I hope, in a new direction. The title says it all: Getting Better: Why Global Development is Succeeding—and How We Can Improve the World Even More.

The book’s author is Charles Kenny, a senior economist on leave from the World Bank and a fellow at the Center for Global Development and the New America Foundation. He writes a weekly column for ForeignPolicy.com as “The Optimist,” but he is a realist, too, and he brings an economist’s eye to this complicated topic.

In making his case, Mr. Kenny is going up against some notable critics. Recent books by writers like Dambisa Moyo and Matt Ridley have depicted aid as wasteful and even damaging to societies. But even some outspoken aid critics have been impressed by “Getting Better.” One of the best known, economist William Easterly, even provided a blurb, praising the book. “You will never look at global economic development the same way again,” he says. To me, that’s exactly right.

Mr. Kenny acknowledges that the billions of dollars that the West has poured into poor countries has had a limited impact on income, which is what most economists use to measure progress in living standards. As he notes, many countries in Africa today have real per-capita incomes lower than that of Britain at the time of the Roman Empire. Over the past several decades, through good times and bad, the income gap between rich and poor countries has grown. And no one really knows why.

But income is only one measure of success and maybe not the most meaningful one. Mr. Kenny shows that quality of life—even in the world’s poorest countries—has improved dramatically over the past several decades, far more than most people realize. Moreover, with reams of solid data to support his case, he argues that governments and aid agencies have played an important role in this progress.

We care about income mostly as a proxy for what money can buy: food, shelter, health, education, security and other factors that contribute to human well-being. Mr. Kenny’s great insight is to point out the flaw in focusing solely on income. Other trends, related to direct measures of quality of life, are much more encouraging.

Fifty years ago, more than half the world’s population struggled with getting enough daily calories. By the 1990s, this figure was below 10%. Famine affected less than three-tenths of 1% of the population in sub-Saharan Africa from 1990 to 2005. As Mr. Kenny suggests, the record has thoroughly disproved Malthusian prophecies of food shortages caused by spiraling population growth. Family sizes have fallen for many decades now in every region, including Africa.

And there’s more good news. Virtually everywhere, infant mortality is down and life expectancy is up. In Africa, life expectancy has increased by 10 years since 1960, despite the continent’s HIV pandemic. Nearly 90% of the world’s children are now enrolled in primary schools, compared with less than half in 1950. Literacy rates in the sub-Saharan region have more than doubled since 1970. Political and civil rights also have gained ground.

The case made by Mr. Kenny in “Getting Better” is a powerful antidote to overly gloomy assessments of development aid. Wasteful and corrupt aid projects are probably inevitable, and they should never be tolerated. But overall, when you look at the big picture, quite a lot of good things are happening.

What’s more, the book suggests ways to make aid more efficient and effective. Mr. Kenny notes that dramatic improvements in quality of life have been achieved even in poor countries where incomes have fallen. How can this be? He credits the spread of new technologies and ideas. Because of them, as he writes, many of “the best things in life are cheap.”

Eradicating smallpox from the face of the Earth, for example, cost about 32 cents per person in infected countries. In just six years, a drive to vaccinate African children against measles reduced the number who died of the disease by three-quarters, from more than 500,000 a year.

Even larger gains in public health can still be achieved at a stunningly low cost relative to the benefits. Of the 10 million children who die each year in poor countries, one-third could be saved through the wider use of breast feeding, insecticide-treated bed nets and oral rehydration therapy (a simple sugar and salt solution) to combat the effects of diarrhea.

Mr. Kenny recommends focusing development aid on helping to spread such ideas and the cheap technologies that can measurably improve quality of life. He suggests, among other things, that we create a global technology bank to fund research or award prizes for advances that particularly benefit the world’s poor.

After years of doom and gloom on the subject of foreign aid, it is refreshing to find so thoughtful and contrarian an approach to the topic. Charles Kenny shines a light on the real successes of aid, and he shows us the benefits that additional smart investment can bring.

The science writer Matt Ridley made his reputation with books like The Red Queen: Sex and the Evolution of Human Nature and Genome: The Autobiography of a Species in 23 Chapters. His latest book, The Rational Optimist: How Prosperity Evolves is much broader, as its title suggests. Its subject is the history of humanity, focusing on why our species has succeeded and how we should think about the future.

Although I strongly disagree with what Mr. Ridley says in these pages about some of the critical issues facing the world today, his wider narrative is based on two ideas that are very important and powerful.

The first is that the key to rising prosperity over the course of human history has been the exchange of goods. This may not seem like a very original point, but Mr. Ridley takes the concept much further than previous writers. He argues that our success as a species, as opposed to earlier hominids, resulted from innate characteristics that allowed us to trade. Not long after Homo sapiens emerged, we were using rare objects, like obsidian blades, far away from the source materials needed to produce them. This suggests that large numbers of commercial links were established even at the hunter-gatherer stage of our development.

Mr. Ridley gives many examples of how exchange allowed groups to thrive, by enabling them, for example, to acquire fish hooks or sewing needles. He also points out that even the most primitive human groups today are open to exchange. I've always thought this openness was surprising, considering the risks involved, but Mr. Ridley convincingly describes its adaptive value.

Exchange has improved the human condition through the movement not only of goods but also of ideas. Unsurprisingly, given his background in genetics, Mr. Ridley compares this intermingling of ideas with the intermingling of genes in reproduction. In both cases, he sees the process as leading, ultimately, to the selection and development of the best offspring.

The second key idea in the book is, of course, “rational optimism.” As Mr. Ridley shows, there have been constant predictions of a bleak future throughout human history, but they haven’t come true. Our lives have improved dramatically—in terms of lifespan, nutrition, literacy, wealth and other measures—and he believes that the trend will continue. Too often this overwhelming success has been ignored in favor of dire predictions about threats like overpopulation or cancer, and Mr. Ridley deserves credit for confronting this pessimistic outlook.

Having shown that many past fears were ultimately unjustified, Mr. Ridley finally turns his “rational optimism” to two current problems whose seriousness, in his view, is greatly overblown: development in Africa and climate change. Here, in discussing complex matters where his expertise is not very deep, he gets into trouble.

Mr. Ridley spends 14 pages saying that everything will be just fine in Africa without our worrying about negative possibilities. This is unfortunate and misguided. Is his optimism justified because things always just happen to work out? Or do good results depend partly on our caring and taking action to prevent and solve problems? These are important questions, and he doesn’t answer them.

In discussing Africa, Mr. Ridley relies on critics who say, essentially, "Aid doesn't work, hasn't worked and won't work." He cites studies, for instance, that show a lack of short-term economic benefit from aid, but he ignores the fact that health improvements, driven by aid, have been a major factor in slowing population growth, which has proven, in turn, to be critical to long-term economic growth. I may be biased toward aid because I spend my money on it and meet with lots of people who are alive because of it, but even if that were not the case, I would not be persuaded by such incomplete analysis.

Development in Africa is difficult to achieve, but I am optimistic that it will accelerate. Science will come up with vaccines for AIDS and malaria, and the “top-down” approach to aid criticized by Mr. Ridley (and by the economist William Easterly) will fund the delivery of these life-saving drugs. What Mr. Ridley fails to see is that worrying about the worst case—being pessimistic, to a degree—can actually help to drive a solution.

Mr. Ridley dismisses concern about climate change as another instance of unfounded pessimism. His discussion in this chapter is provocative, but he fails to prove that we shouldn't invest in reducing greenhouse gases. I asked Ken Caldeira, a scientist who studies global ecology at the Carnegie Institution for Science, to look over this part of the book. He pointed out that Mr. Ridley celebrates declining air pollution emissions in the U.S. but does not acknowledge that this has come about because of government regulations based on publicly funded science, which Mr. Ridley opposes. As Mr. Caldeira rightly observes, “It is a wonder of development that our economy can grow as air pollution diminishes.” What is true of the U.S. case, I’d suggest, can be true of the world as a whole as we deal with the challenges posed by climate change.

The Rational Optimist would be a great book if Mr. Ridley had wrapped things up before these hokey policy discussions and his venting against those he considers to be pessimists. I agree with him that some people are overly concerned with potential problems, and I hadn't realized that this pessimism was so common in rich countries over the last several centuries. As John Stuart Mill said in 1828, in a quote from the book that I especially enjoyed: “I have observed that not the man who hopes when others despair, but the man who despairs when others hope, is admired by a large class of persons as a sage.”

The most obvious instance of excessive pessimism in Mills’s era was the Communist Manifesto. In one of history’s great ironies, Karl Marx used the profits from the German textile mills of Friedrich Engel’s father to support the writing and distribution of a political philosophy based on pessimism about capitalism.

Pessimism is often wrong because people assume a world where there is no change or innovation. They simply extrapolate from what is going on today, failing to recognize the new developments and insights that might alter current trends. For too long, for instance, population forecasts have ignored the possibility that population growth would ease as the world became better off, because people who are wealthier and healthier do not feel the need to have so many children. (For more on this issue, see the excellent presentations on the Gapminder website of the development expert Hans Rosling.)

A lot of the rhetoric about sustainability implicitly assumes that we will exhaust our natural resources, as though there will never be any substitution of one commodity for another in the future. But there has always been such substitution. The late economist Julian Simon made a famous wager with the biologist Paul Ehrlich, author of The Population Bomb. In response to Mr. Ehrlich’s prediction that population growth would lead to resource scarcity and mass starvation, Simon bet him that the cost of a basket of commodities, including copper, chromium and nickel, would actually decrease between 1980 and 1990. Mr. Simon won the bet because he believed that, despite increased demand, increased supply would win out. And in fact, to take one example, fiber optics soon took the place of copper wire in many communications technologies.

There are other potential problems in the future that Mr. Ridley could have addressed but did not. Some would put super-intelligent computers on that list. My own list would include large-scale bioterrorism or a pandemic. (Mr. Ridley briefly dismisses the pandemic threat, citing last year’s false alarm over the H1N1 virus.) But bioterrorism and pandemics are the only threats I can foresee that could kill over a billion people. (Natural catastrophes might seem like good candidates for concern, but I’ve been persuaded by Vaclav Smil, in Global Catastrophes and Trends, that the odds are very low of a large meteor strike or a massive volcanic eruption at Yellowstone.)

Even though we can't compute the odds for threats like bioterrorism or a pandemic, it’s important to have the right people worrying about them and taking steps to minimize their likelihood and potential impact. On these issues, I am not impressed right now with the work being done by the U.S. and other governments.

The key question that Mr. Ridley fails to address is: What's wrong with worrying about and guarding against threats that might become real, large problems? Parents worry a great deal about their children's safety. Some of that worry leads to constructive steps to keep children safe, and some is just negative emotion that doesn't help anyone. If we all agree to join Mr. Ridley as rational optimists, does that mean that we should stop worrying about trends that might cause problems and not take action to anticipate them?

Mr. Ridley devotes his attention to just two present-day problems, development in Africa and climate change, and seems to conclude, "Don't worry, be happy." My prescription would be, "Worry about fewer things while understanding the lessons of the past, including lessons about the importance of innovation." This might qualify me as a rational optimist, depending on how stringent the criteria are. But there can be no doubt that excessive pessimism may cause problems with how society plans for the future. Mr. Ridley's book should trigger in-depth discussions on this important subject.

Like many other authors who write about innovation, Mr. Ridley suggests that all innovation comes from new companies, with no contribution from established companies. As you might expect, I disagree with this view. He also seems to think that innovation involves simply coming up with a new idea, when in fact the execution of the idea is critical. He quotes the early venture capitalist Georges Doriot as saying that as soon as a company succeeds, it stops innovating. A great counterexample is Intel, which developed over 99% of its breakthroughs after its first success.

Mr. Ridley describes the economy of the future as "post-corporatist and post-capitalist," a silly throwaway phrase. He never explains what will replace all the companies that figure out how to make microchips or fertilizer or engines or drugs. Of course, many companies will come and go – that is a key element of capitalism – but corporations will continue to drive most innovation. It is a dangerous and widespread problem to underestimate the ongoing innovation that takes place within mature corporations.

In his quest to highlight exchange as the key mechanism in the success of our species, Mr. Ridley underplays the role of other institutions, including education, government, patents and science, all of which, especially since the 19th century, have played a central role in the improvements that humanity has experienced. Too often, when Mr. Ridley finds an example that minimizes the contributions of these institutions, he seems to think that he has validated the idea that exchange deserves all of the credit.

I am always amazed by scientific possibilities. Electricity, steel, microprocessors, vaccines and other products are possible only because of our efforts to understand the world and how it works. The scientists and tinkerers who investigate these mechanisms are engaged in a profound process of discovery. Without their curiosity and creativity, no amount of exchange would have produced the world in which we now live.

Vaclav Smil has written another very informative book called Why America is Not a New Rome. This is the third book of his to come out this year. I have previously reviewed and recommended both of the others, which focus on energy. Although energy is not the primary topic of this book, Smil still does his normal, thorough, fact-driven logical job on this topic.

After reading so many articles and speeches predicting what will happen to America because of some supposed similarities to the Roman Empire, Smil felt it was important to explain that there is no predictive power in these comparisons. Smil is a great student of history, including Roman history and the dynamics of its Empire over time. Even though I took five years of Latin and enjoyed being able to understand some of the quotes in the book, my understanding of the Roman Empire was greatly expanded by reading this book.

Smil points out that the Roman Empire went through many phases over nearly two millennia–starting with a Republic and then with an Emperor and finally splitting into a Western Empire and Eastern Empire. The western part died out about 500 C.E. and the eastern part lasted until 1453. Although many theories have been put forward about what factors finally led to the empire’s demise, historians do not agree.

The key point of the book is that more than 1,500 years separate our current era from Roman times, and life has changed so much that any sense of similarity is illusory. In Roman times, people had barely enough food to sustain them. Human and animal muscle power comprised virtually the entire kinetic energy source. Life expectancy was between 20 and 30 years. Income levels were a fraction of what we have today. So the dynamics of “surviving” were completely different then.

Smil makes an important point regarding scientific and technical advances. Whereas U.S. innovation has played a central role in creating a modern global civilization in less than 150 years, “the Roman Empire had an unremarkable…record in advancing scientific understanding, and its overall contributions to technical and engineering innovations were…fairly limited.” By contrast, he notes, China’s Han dynasty, which overlapped several centuries with the Roman Empire, was far more innovative in ways that changed the world—such as the invention of paper, iron, ploughs, harnesses and many important nautical advances.

The primary similarity that Smil finds between the U.S. and ancient Rome is that people overestimate the dominance of both. At its peak, the Roman Empire comprised 12 percent of the world’s population. At the turn of the millennium, the U.S. represented just 4 percent of the global population. Militarily, the Roman Empire never controlled most of the world, just as the U.S. does not today.

Smil makes the case that the U.S. is not an empire by any reasonable definition of the word. Economically, the U.S. percentage of the world’s economic product in 2005 was 22.5 percent, with China, Brazil, Russia and many countries in the European Union continuing to gain in economic strength.

You could argue that America has some level of hegemony, but that is the strongest word that applies to our position. It is certainly interesting to discuss how the U.S. position will change in the future, but reaching back to Roman analogies will not aid in that discussion. Most references to Rome simply talk about things that are common to all large and long-lasting governments—complexity, disagreement, and some level of failed ambition.

Anyone expecting Smil to forecast the future of America will be disappointed but he does allude to a number of trends that are of serious concern. I hope this book will help us focus on fixing these trends without thinking that analogies from the Roman Empire will help us find the right approach.

I had a chance to read a prepublication copy of SuperFreakonomics: Global Cooling, Patriotic Prostitutes And Why Suicide Bombers Should Buy Life Insurance before it was officially released.

I really liked Freakonomics and I think SuperFreakonomics is even better.

Steven Levitt and Stephen Dubner like to cover a lot of ideas, in contrast to Malcolm Gladwell, whose books I like a lot too. Gladwell tends to take a few ideas and illustrate them in depth with a lot of examples.

I recommend this book to anyone who reads nonfiction. It is very well written and full of great insights.

I could be accused of bias in recommending it because I had some limited involvement in three of the stories.

In discussing U.S. health care, the authors work with Craig Feied and Mark Smith to use the data-gathering software now called Almaga which was bought by Microsoft. It is an amazing piece of technology with its ability to let you look at patient trends. The book explains how this data can be used to look at the quality of doctors and different medical procedures.

When they talk about how you might reduce hurricane damage, they mention Nathan Myhrvrold and the team at Intellectual Ventures and their idea to mix hot water on the surface of the ocean with cooler water below to reduce hurricane strength. Unfortunately the authors don’t figure out how the economics should work and who would authorize an experiment that would change the local weather with mostly good effects, but perhaps some bad effects as well.

When they focus on global warming they again mention Intellectual Ventures and you meet Lowell Wood and Ken Caldeira for a discussion of how geoengineering can probably delay the effects and provide many extra decades to make the changes in energy production and use that are necessary. Levitt and Dubner do a great job of describing the idea but don’t go into the question of how it should be applied.

One of my favorite things in the book is the debunking of many of the studies economists have done that they use as the basis for claiming that people are irrational in their choices. Dubner and Levitt cover new research that shows that the wrong conclusions were drawn. I think what researchers are seeing is a reflection of the social rewards/risks for the students involved in the tests rather than some basic flaw in human economic thinking.

The book also talks about how people underestimate how much life has improved in every way during the last 100 years. The example they use is the risk of dying in childbirth and how that has changed. They also talk about progress on diseases (particularly vaccines such as polio) and car safety. I knew that seat belts were an amazing intervention but I hadn’t realized how little extra safety airbags and children’s car seats provide on top of what is provided by the full use of seat belts.

One area where the book doesn’t quite get the story right is in discussing how important nitrogen fertilizer was in increasing food production. The Vaclav Smil book Enriching the Earth: Fritz Haber, Carl Bosch and the Transformation of World Food Production tells this incredible story in great depth. SuperFreakonomics talks about ammonium nitrate as if it was the silver bullet that made the advance possible. There was some ammonium nitrate that was mined from South America but that quickly ran out. The real advance was the process to extract nitrogen gas from the air and turn it into the nitrogen compounds that plants can use.

There are tons more things in this book that you will find cool that I don’t mention.