Remember the population explosion? When population was growing at its fastest rate in human history in the decades after World War II, the sense that overpopulation was stunting economic development and stoking political instability took hold from New Delhi to the United Nations’ headquarters in New York, sending policy makers on an urgent quest to stop it. In the 1970s the Indian government forcibly sterilized millions of women. Families in Bangladesh, Indonesia and elsewhere were forced to have fewer children. In 1974, the United Nations organized its first World Population Conference to debate population control. China rolled out its one-child policy in 1980. Then, almost as suddenly as it had begun, the demographic “crisis” was over. As fertility rates in most of the world dropped to around the replacement rate of 2.1 children per woman — with the one major exception of sub-Saharan Africa — population specialists and politicians […]