Why Population Predictions Bomb

One of the central “policy problems” faced in modern societies is population growth. I used the scare quotes because it’s not clear that population is a state issue at all, much less a problem.

Population, after all, is the sum of the consequences of millions of individual actions, some of them choices and some just actions. A woman has a certain number of children, for complex reasons. If we add up the results within a nation, the result is the growth overall in the population. Or, in many nations, decline.

The reasons vary substantially across the individuals involved: availability of contraception, social norms, family pressures, or sexual violence and the problems of political stability all play a role. Thinking of the aggregate as a single variable factor—“population”—something that can be manipulated by changing policies—is a strange conceit of central planners.

There has been a lot of famously breathless worrying about population growth. One of the first, of course, was Thomas Malthus, whose views were actually more complex than the “population crisis” claim we find in his followers.

Bad Predictions

Perhaps the most famous Malthusian doomsayer is Paul Ehrlich, who famously said, “The battle to feed all of humanity is over. In the 1970's and 1980's hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.” That was in his extremely influential 1968 book, The Population Bomb. Ehrlich went on to predict that

At this late date nothing can prevent a substantial increase in the world death rate…The train of events leading to the dissolution of India as a viable nation is already in motion... If I were a gambler, I would take even money that England will not exist in the year 2000.

That’s some serious hogwash, there. The population of India was 530 million when this “prediction” was made; India has more than 1.34 billion in 2018, and there is less poverty, not more.

Further, readers may recall that Ehrlich was a gambler; he foolishly took Julian Simon’s famous bet on commodity prices. Ehrlich lost, of course, but never came close to admitting that he was in any way mistaken.

In 1969 Ehrlich predicted that life expectancy in the U.S. life “will drop to 42 years by 1980 due to cancer epidemics.” I could go on; there are hundreds more very specific predictions about disaster that have been not only wrong, but qualitatively in the wrong direction.

Every time Ehrlich and other population alarmists have said “down” the actual result was “up”: Population has increased without causing major problems; the biggest problems of poverty in most countries are obesity, not starvation; and the world is less polluted and the air is cleaner (for everything except carbon dioxide, a problem Ehrlich never mentioned even once) than it was in the 1960s. Things are better, not worse, and things are better most of all for the poor.

In a sense, Ehrlich has been consistent: every ten years or so he just adds another decade to his fatuous “predictions” and barfs up a new batch of nonsense. And he has managed to get paid a fortune to do it. The point is that it’s not surprising that a seller of ideological snake oil would continue to sell the same useless concoction of nonsense, as long as people want to line up to buy it. But that raises the real question: why would anyone buy this nonsense? How could a fake scientist continue to be listened to, and even respected, when not one of his specific predictions are even in the correct direction?  

I have an answer. And I have to admit I hope I’m wrong, because if I’m right it’s a pretty horrible indictment of the moral impoverishment of the population alarmists. But hear me out, and see what you think.


Population is a Problem, Unless You Have Capitalism


The answer to population growth is capitalism. Commodifying labor. Yes, I went there. Full on accepting the worst-case characterization of the left. Not “market system.” Capitalism. Let’s own it.

The reason that capitalism solves the population problem requires a little explanation, though it’s not really very complicated. Every society that has adopted a capitalist system has seen wages for labor rise sharply. As Benjamin Powell shows in his remarkable book, Out of Poverty, countries that start out with poverty and out-of-control population growth see those problems solved, in just two or three generations. If you line countries up in “event time”—so that you are comparing countries at the point they adopt capitalism, even if that happened centuries apart—a striking parallel emerges. Wages rise, poverty falls, and population growth shrinks to replacement.

It happened in northern Europe by 1975; it happened in Japan in 1970; in Korea and Taiwan in 1980; and in several Latin American nations, the end of population growth has been seen in the past two decades. Some nations are still growing, but much of that growth is from immigration rather than births above the replacement rate.

When do nations see their fertility rates, defined as births per woman, fall? When labor is priced; that’s what capitalism does, putting a price on labor. If a woman is educated and allowed to work, the opportunity cost of her time skyrockets, and she becomes far more valuable to the society—and to herself—to have a child every 18 months or two years.

Nations that develop capitalist institutions see median age of first children rise, and the total number of children fall dramatically. China’s birthrate had fallen below replacement by 1995 (though the “one-child” policy was a big part of the cause), and India’s fertility fell from nearly 6 in 1960 to 2.3, or just above replacement, in 1015.  

Since becoming wealthy also decreases infant mortality rates, and increases life expectancy, it’s actually surprising that the number of nations at or below replacement fertility is growing so rapidly. If more children survive, and people live longer, the replacement rate falls. But nonetheless, it’s true: population growth is disappearing all over the world in nations that start to use the price system.

This shows the real underlying problem with the “analysis” of Ehrlich and his acolytes. Ehrlich, to his credit, is quite clear about this, writing in 1969: “We've already had too much economic growth in the US. Economic growth in rich countries like ours is the disease, not the cure.”

Hating Prosperity

The alarmists’ real concern is not the growth of population; it’s prosperity. Their concern is that the resources of the earth will be used up, and that humanity has to prepare by becoming fewer and poorer. But all the evidence points in the opposite direction.

The solution to the population problem is also the right thing to do, morally. In countries without capitalist institutions patriarchal institutions oppress women and relegate them to reproductive slavery. This means that the opportunity cost of women’s time is too low.  Only capitalism values women, and only capitalism can end the population crisis.

The solution is deceptively simple: develop capitalism, and educate the female population to enable them to join the workforce. All the countries in the world that educated female populations and market institutions have fertility rates right around replacement. There is no population problem; there is only a “not enough capitalism—yet!” problem.

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Michael Munger

Michael Munger is Professor of Economics at Duke University and Senior Fellow of the American Institute for Economic Research. His degrees are from Davidson College, Washingon University in St. Louis, and Washington University.