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The Problem with Shrinkage

Some experts claim that falling fertility rates and declining populations are good for us. They're wrong.

11:00 PM, Dec 13, 2006 • By JONATHAN V. LAST
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FERTILITY RATES around the world are dropping for a variety of complex reasons (see "The Population Sink" and "Darwin's End"). While population itself continues to increase--the United States, for instance, recently passed the 300 million mark--this is the product of waning demographic momentum. The rate of increase is slowing, and, by 2080, world population will peak somewhere in the vicinity of nine billion before contracting.

Which leads us to the next question: Is population contraction a bad thing?

Some think not. There is a school of thought that argues that smaller populations are good. Population-control proponents claim variously that:

We do not have the food to sustain higher populations.

Our planet already suffers from overcrowding.

The environmental impact of increased populations will bring catastrophe either through pollution or consumption of finite natural resources.

Decreased population will lead to higher wages and a better quality of life as available supplies exceed reduced demands.

These arguments seem reasonable at first, but do not withstand scrutiny.

Let's start with food. The worry about mass starvation is a remnant of Paul Ehrlich's 1968 sensation The Population Bomb. Ehrlich wrote that, in the face of expanding populations, "the world will undergo famines--hundreds of millions of people are going to starve to death."

As Ehrlich himself admits, this prediction proved faulty. Instead, the availability of food has greatly increased, even with growing population. Demographer Philip Longman notes that, between 1980 and 2001, the price of food declined by 53 percent. Famine, observes Longman, has become "a political problem--a matter of fair distribution, not of inadequate supply."

How did this happen? The Danish economist Ester Boserup upended the classical Malthusian model of agriculture in 1965 by proposing that population increase fosters agricultural innovation, which, in turn, spurs leaps in production. Her theories have been borne out.

What about overcrowding? Everywhere you go today, you find traffic jams and sprawl, with people packed into condominiums and crowded malls. But this is a problem of density, not population. There's plenty of land available out there. The problem is that people who used to live in the countryside have relocated to cities: There are fewer people living in the Great Plains today than there were in the 1920s.

Environmental concerns are more interesting. However, such end-of-the-world warnings are not new. In the 1970s, many scientists were concerned about a new Ice Age. But leave aside global warming, on which science is conflicted, and take the other concern principally cited by environmentalists: that the Earth has a finite supply of resources that we shall surely soon deplete.

This, too, is an argument we have heard before. As Massimo Livi-Bacci explains in his Concise History of World Population, more than 100 years ago, economists "feared that coal supplies would be used up, and about 30 years ago the Club of Rome made similar predictions regarding other raw materials." Instead, markets and human innovation stepped in to provide greater efficiency.

For instance, in the America of 1850, you needed an average of 4.6 tons of petroleum equivalent to produce $1,000 of goods and services. By 1950, you needed only 1.8 tons, and, by 1978, 1.5 tons. Markets are exceptional engines of conservation.

Which leaves us with the economy. In 1971, Simon Smith Kuznets won the Nobel Prize in economics for his theory of "tested knowledge." As Kuznets explained: "More population means more creators and producers, both of goods along established production patterns and of new knowledge and inventions."

Kuznets was codifying what others had noticed before. Adam Smith remarked that "the most decisive mark of the prosperity of any country is the increase of the number of its inhabitants." As Livi-Bacci observes, "All things being equal, population increase leads to increased per capita production."

So the proposed "benefits" of population decline are, at the very least, suspect.

On the other hand, there are worrying potential costs of population decline. Of course, this worry is theoretical because we've never seen population decline on the massive scale that's coming our way. Or rather, we've never seen it in the modern world. There are, however, two historical examples.