The man who bet against humanity — and lost

On February 9, 1970, Johnny Carson did something that would be unthinkable for a late night host today, or really anyone on TV: He gave a full hour of The Tonight Show to a Stanford professor.

But Paul Ehrlich, the author along with his wife Anne of the blockbuster book The Population Bomb, was charismatic, telegenic, and absolutely terrifying. He told Carson’s massive audience that hundreds of millions of people were about to starve to death. Nothing could stop it.

Ehrlich’s first appearance on The Tonight Show demonstrates a lot of things, not least how much popular TV has changed. (I’m struggling to imagine Carson’s eventual successor Jimmy Fallon giving an hour to, say, CRISPR inventor Jennifer Doudna — and without even doing a lip sync battle.) But it also shows just how influential Ehrlich was.

He would go on The Tonight Show more than 20 times. The Population Bomb sold over 2 million copies and became one of the most popular science books of the 20th century. His work helped popularize a broader population-panic worldview that influenced policymakers in the US and abroad, including coercive family-planning policies in countries such as India and China. Ehrlich and his book fundamentally changed the world we live in today.

And yet Ehrlich, who died last week at 93, turned out to be spectacularly wrong, wrong in ways that had major consequences for humanity. But precisely because he was wrong and yet so influential, understanding why his views were so popular is necessary for understanding why doomsaying remains so seductive — and so dangerous. 

The book that went off like a bomb

The Population Bomb, I suspect, was one of those of-the-moment books that was more owned than read. But you didn’t need to get far into it to grasp Ehrlich’s alarmist message. You just needed to read the opening lines: “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.”

And the book was just part of his lifelong campaign. Ehrlich predicted that 65 million Americans would die of famine between 1980 and 1989. He told a British audience that by the year 2000, the United Kingdom would be “a small group of impoverished islands, inhabited by some 70 million hungry people.” He said India — which was home to nearly 600 million people in 1970 — could never feed 200 million more people. He said US life expectancy would drop to 42 by 1980. On Earth Day 1970, he declared that “in 10 years all important animal life in the sea will be extinct.”

Every one of these predictions was almost 180 degrees in the wrong direction. In America, as in much of the world, obesity became the true metabolic health crisis, not starvation. The UK — at least the last time I checked — still exists. India is now a major agricultural exporter, and its population has nearly tripled while hunger has fallen. Marine life is stressed but very much not extinct.

The bottom line is that instead of mass starvation, the world experienced the greatest expansion of food production in human history. Global cereal production today exceeds 3 billion tonnes, a roughly threefold increase from 1970. Per capita calorie supply has risen consistently since 1961. Since The Population Bomb was published, rates of hunger have dropped precipitously. 

When the wrong lines go up

What did Ehrlich miss? For one thing, he made a common mistake: He assumed “line go up.” 

The years leading up to The Population Bomb’s publication in 1968 featured the steepest population increases in global history. The trends were so on the nose for his thesis that you could almost forgive Ehrlich for assuming they would inevitably continue.

But a closer look at the data would have revealed that even in the high-growth 1960s, the world was already beginning a demographic transition that would lead us to our comparatively low-fertility present. Europe, Japan, and North America were all seeing their fertility rates fall as societies urbanized, women were educated, and child mortality dropped. The theories explaining that demographic transition were already decades old by 1968, which was also eight years after the birth control pill was introduced.

Ehrlich — and many others of his time, to be fair — appeared to assume that these patterns wouldn’t apply as the countries of the Global South developed. But they did. As these social and economic trends spread around the world, fertility kept falling, from around five children per woman globally when The Population Bomb was published to 2.3 today, which is barely above the population replacement rate of 2.1.

But the bigger mistake wasn’t misreading demographics. It was failing to account for people like Norman Borlaug.

Borlaug was an agronomist from rural Iowa who, with the support of the Rockefeller Foundation, developed high-yielding dwarf wheat varieties that transformed agriculture in countries like Mexico, India, and Pakistan. India, which Ehrlich had written off in racially tinged ways, didn’t just avoid famine; it became self-sufficient in food production.

The Population Bomb was explicit about Ehrlich’s worldview: Population growth was “the cancer” that “must be cut out.” He saw people — or at least, people in the Global South — as little more than mouths to feed, each fighting for shares of a static pie. Borlaug and the Green Revolution researchers, by contrast, saw them as minds to solve problems, including figuring out ways to make the pie bigger. Ehrlich’s fundamentally zero-sum worldview may have gotten him global recognition — and sadly, remains far too prevalent — but it blinded him to the future.

And that’s why he ended up on the losing end of one of the most famous wagers in academic history. 

The bet that explains the world

Julian Simon, an economist at the University of Maryland, believed the opposite of everything Ehrlich believed. Simon’s argument was simple: People are the world’s most valuable resource. Human ingenuity responds to scarcity by finding new supplies, substitutes, and efficiencies. And that meant that commodity prices, adjusted for inflation, would fall over time — not rise.

In 1980, Simon challenged Ehrlich to a bet: Pick any raw materials, any time period longer than a year, and wager on whether prices would go up or down. Ehrlich and two colleagues chose five metals — chromium, copper, nickel, tin, and tungsten — and bought $1,000 worth on paper. The bet would be settled in 1990. During those 10 years, the world’s population grew by more than 800 million — the largest one-decade increase in human history.

Ehrlich was wrong. (Again.) All five metals fell in inflation-adjusted price. In October 1990, Ehrlich acknowledged Simon’s win with a check for $576.07.

What Ehrlich didn’t do was revise his views to reflect the facts, which is what makes him more than a cautionary tale about bad predictions. In 2009 he told an interviewer that The Population Bomb was “way too optimistic.” In 2015 he said his language “would be even more apocalyptic today.” On 60 Minutes in 2023, at age 90, he told Scott Pelley that “the next few decades will be the end of the kind of civilization we’re used to.”

It didn’t matter that the world had spent 55 years proving him wrong. Ehrlich didn’t blink.

And Ehrlich’s wrongness had real consequences. He endorsed cutting off food aid to countries he considered hopeless, including India and Egypt. The broader population-panic movement Ehrlich helped create influenced coercive real-world policies: India’s forced sterilization campaigns during the 1970s, China’s one-child policy, and sterilization programs across the developing world.

The dangerous appeal of doomsaying

So why did the world listen for so long? Partly because we’re wired to. As readers of this newsletter know, humans process negative information more readily than positive, an evolutionary hangover that makes doomsayers inherently more compelling than optimists. And Philip Tetlock’s research on expert prediction found that “hedgehog” thinkers — people who, like Ehrlich, see everything through the lens of one big idea, and fight like hell to hold onto it — are simultaneously the worst forecasters but get the most media attention. They’re more confident, more quotable, more dramatic. The hedgehog gets Carson. The fox gets ignored.

There’s also a structural incentive problem. Predict things will be fine and you’re wrong? You’re irresponsible. Predict disaster and you’re right? You’re a genius. Predict disaster and you’re wrong? People forget — or just assume you were a little early. (It was notable to me that the subheadline of the New York Times obituary of Ehrlich called his predictions not wrong, but “premature.”)

None of this means we should ignore environmental problems. Climate change is real, and Ehrlich was relatively early in flagging it. Biodiversity loss — closer to his actual academic expertise in entomology — remains genuinely alarming. And we shouldn’t repeat Ehrlich’s mistakes in the opposite direction. Just because things have been getting better does not automatically mean that trend will continue, especially if we make perverse and self-defeating policy choices.

But the real lesson of Ehrlich’s life is that assuming doom leads to worse policy than assuming agency. Write off a country as hopeless, and you justify cutting its food aid. Assume people are the problem, and you end up sterilizing them against their will.

Julian Simon died in 1998, never approaching Ehrlich’s level of public fame. His signature line: “The ultimate resource is people — skilled, spirited, and hopeful people who will exert their wills and imaginations for their own benefit as well as in a spirit of faith and social concern.”

That might not have played as well on The Tonight Show. But it’s the formula for a much better world.