Which Is Better, a Larger or Smaller Population?

• Author: Lemieux, Pierre

Is population stagnation or decline a good thing or a bad thing? Last year, China's population declined for the first time in six decades, partly because of government limitations dating from the mid-20th century on the number of children per family. Many observers assume the decline is bad and that population growth is a good thing.

But this belief is often based on state interests. A large population is good because it provides conscripts and cannon fodder for the state in times of war. And a growing population generates new taxpayers to finance social programs for the elderly such as Social Security and Medicare.

On the other hand, since the 1970s, environmentalists have been recycling Thomas Malthus's arguments to claim that population stagnation or decline would be good because it would prevent or reverse environmental catastrophes. In his 1968 book The Population Bomb, Stanford biologist Paul Ehrlich warned that an exploding world population was hitting resource constraints and that, within a decade, food and water scarcity would result in a billion or more people starving to death. Governments, he opined, should work toward an optimal world population of 1.5 billion, a goal corresponding to 57 percent less than the actual population in 1968 and 81 percent less than today's 7.9 billion. In 1965, the New Republic announced that the "world population has passed food supply," and that world hunger would be "the single most important fact in the final third of the 20th Century." The "freedom to breed is intolerable," ecologist Garrett Hardin pontificated. Of course, those grim predictions haven't borne out.

Better arguments / Economics and philosophy offer analyses of population size and growth that are preferable to simplistic governmental and environmentalist viewpoints.

A major economic argument in support of population growth is that, ceteris paribus, more humans mean more trading partners and thus better opportunities for all. The late economist Julian Simon offered a related argument that more people increase the flow of human ingenuity, inventions, and new solutions for human problems.

In the field of religious ethics, Christianity and perhaps especially Catholicism have preached that married couples have a moral duty to engage in the creation of human beings with immortal souls. The larger the population, the better. One corollary seems to be that women should spend their fertile years having babies. At least in advanced...