Forget the prophecies saying overpopulation will starve the planet. The human race is approaching the point where it’s no longer reproducing enough to expand the global headcount. In the world’s biggest economies -- the U.S., China, Japan and Germany -- it’s already happening or will soon. Economists say these countries could see slower economic growth unless they increase their working-age populations by accepting immigrants, possibly from regions with higher fertility rates, like parts of Asia and Africa. Lower fertility rates -- the number of live births per woman -- could also threaten safety-net programs like pensions and health care.
Fertility rates have dropped globally to about 2.4 this decade, from 5 in the 1960s, according to the World Bank. That’s getting close to the rate, about 2.1, required to keep the world’s population stable in the long run. Many wealthier countries, particularly in Europe, are well below 2.1. Several nations -- Moldova, South Korea, Singapore -- share the world’s lowest fertility rate of 1.2. Most developing nations have much higher rates, with many in Africa at 5 or above.