ABSTRACT
Population explosion is the most extreme ever recorded but, in fact, episodes of rapid population growth have occurred throughout human history. The trigger has been some new opportunity, such as settled agriculture. A few—but influential—demographers, including Frank Notestein of the Population Council, predicted that modernization, urbanization, and reduction in child mortality would cause a transition to small family size, that is, a "demographic transition" to low mortality and low fertility rates. Symptoms of population pressure included a rigiditying class structure, war, and famines that struck from the twelfth through the fourteenth centuries. A different kind of opportunity preceded the explosive "medieval increase" in population recorded for western Europe. With mortality lowered by foreign public-health and medical interventions but with fertility still high, populations grow fast and then faster. In Africa as well, trade, foreign aid, and independence from colonial powers coincided with rapid and still more rapid population growth. Again, euphoria promoted high fertility.
