Falling fertility rates
In the 1960s, scholar Paul R. Ehrlich warned that a looming global population explosion would usher in mass starvation and death by the end of the 20th century. If recent data are any indication, Ehrlich’s fears may have been somewhat misplaced. For the past several decades, fertility rates have steadily declined around the world. But many analysts agree that those falling figures are tied to another set of problems. According to the experts, parts of the world are facing a new “demographic time bomb,” one that threatens skyrocketing health care and pension costs as populations age. The threat also could undermine the economies of many nations by robbing them of young, homegrown workers entering the labor force. “It was really a shocking realization that this was happening,” said Mary Brinton, Radcliffe Hrdy Fellow and chair of Harvard’s sociology department. For the past several years, Brinton and a team of collaborators that includes several...