Range - David Epstein Page 0,88

environmental advisers recommend a one-child policy and sterilization of people with low IQ scores. Russia, China, and the United States are dragged into nuclear war, which renders the northern two-thirds of Earth uninhabitable. Pockets of society persist in the Southern Hemisphere, but the environmental degradation soon extinguishes the human race. In the “cheerful” scenario, population controls begin. The pope announces that Catholics should reproduce less, and gives his blessing to abortion. Famine spreads, and countries teeter. By the mid-1980s, the major death wave ends and agricultural land can begin to be rehabilitated. The cheerful scenario only forecast half a billion or so deaths by starvation. “I challenge you to create one more optimistic,” Ehrlich wrote, adding that he would not count scenarios involving benevolent aliens with care packages.

Economist Julian Simon took up Ehrlich’s challenge to create a more optimistic picture. The late 1960s was the prime of the “green revolution.” Technology from other sectors—water control techniques, hybridized seeds, management strategies—moved into agriculture, and global crop yields were increasing. Simon saw that innovation was altering the equation. More people would actually be the solution, because it meant more good ideas and more technological breakthroughs. So Simon proposed a bet. Ehrlich could choose five metals that he expected to become more expensive as resources were depleted and chaos ensued over the next decade. The material stakes were $1,000 worth of Ehrlich’s five metals. If, ten years hence, prices had gone down, Ehrlich would have to pay the price difference to Simon. If prices went up, Simon would be on the hook for the difference. Ehrlich’s liability was capped at $1,000, whereas Simon’s risk had no roof. The bet was made official in 1980.

In October 1990, Simon found a check for $576.07 in his mailbox. Ehrlich got smoked. The price of every one of the metals declined. Technological change not only supported a growing population, but the food supply per person increased year after year, on every continent. The proportion of people who are undernourished is too high until it is zero, but it has never been so low as it is now. In the 1960s, 50 of every 100,000 global citizens died annually from famine; now that number is 0.5. Even without the pope’s assistance, the world’s population growth rate began a precipitous decline that continues today. When child mortality declined and education (especially for women) and development increased, birth rates decreased. Humanity will need more innovation as absolute world population continues to grow, but the growth rate is declining, rapidly. The United Nations projects that by the end of the century human population will be near a peak—the growth rate approaching zero—or it could even be in decline.

Ehrlich’s starvation predictions were almost magically bad. He made them just as technological development was dramatically altering the global predicament, and right before the rate of population growth started a long deceleration. And yet, the very same year he conceded the bet, Ehrlich doubled down in another book. Sure, the timeline had been a little off, but “now the population bomb has detonated.” Despite one erroneous prediction after another, Ehrlich amassed an enormous following and continued to receive prestigious awards. Simon became a standard-bearer for scholars who felt that Ehrlich had ignored economic principles, and for anyone angry at an incessant flow of dire predictions that did not manifest. The kind of excessive regulations Ehrlich advocated, the Simon camp argued, would quell the very innovation that had delivered humanity from catastrophe. Both men became luminaries in their respective domains. And both were mistaken.

When economists later examined metal prices for every ten-year window from 1900 to 2008, during which time world population quadrupled, they saw that Ehrlich would have won the bet 62 percent of the time. The catch: commodity prices are a bad proxy for population effects, particularly over a single decade. The variable that both men were certain would vindicate their worldviews actually had little to do with them. Commodity prices waxed and waned with macroeconomic cycles, and a recession during the bet brought the prices down. Ehrlich and Simon might as well have flipped a coin and both declared victory.

Both men dug in. Each declared his faith in science and the undisputed primacy of facts. And each continued to miss the value of the other’s ideas. Ehrlich was wrong about population (and the apocalypse), but right on aspects of environmental degradation. Simon was right about the influence of human ingenuity on the food and energy supply, but wrong in claiming that improvements