Jonathan V. Last, writing in the Wall Street Journal:
In 2004, the United Nations published demographic projections suggesting that the world in general, and the West in particular, was in real trouble: Persistently low fertility meant that the population of most industrialized nations would shrink in the coming decades. The U.N. report seemed to crystallize decades of increasingly gloomy predictions.
In order for a country to maintain a steady population, it needs a fertility rate of 2.10. If the rate is higher, the country's population grows; lower and it shrinks. Since the late 1960s, fertility rates in every corner of the world have been falling, fast. While demographers once worried about overpopulation, a hysteria rooted in 1960s and 1970s Malthusianism, the exact opposite occurred. Fertility rates were so low that the world's population would wind up contracting. Forty years of falling fertility put nearly every First World country on the path toward shrinkage—and the plummeting fertility in developing nations meant that the Third World would not be far behind.
There was much hand-wringing. Japan, for instance, was projected to fall to a population of 112 million in 2050, from 128 million in 2005. Italy would shrink to 51 million from 58 million. Poland would go to 32 million from 39 million, and so forth. Total world population by 2050, the U.N. predicted, would be 9.1 billion, with the rate of growth slowing to a crawl and global contraction just a decade or two away. Historically, population contraction has never been accompanied by prosperity. We have only witnessed it at times of great upheaval—during the decline of the Roman Empire, or as the Black Death swept Europe.
In recent years, nearly every demographic study has painted a dire picture of the world's changing demographics. Yet when the U.N. issued its latest report this past May, it seemed almost sunny.
Whole thing here.