It's not just the industrialized nations. It takes about two generations for a country to drop from a high birth rate to a birth rate of less than two (replacem

It's not just the industrialized nations. It takes about two generations for a country to drop from a high birth rate to a birth rate of less than two (replacement, more or less). All but a handful of impoverished, war-torn countries in Africa and the Middle East are deep into this cycle or through it already.