“Why so few babies?” asked a New York Times essay that sounded oddly familiar to me. In my college days, it seemed that everybody was talking about “The Population Bomb,” the 1968 bestseller in which Stanford biologist Paul R. Ehrlich predicted worldwide famines and other dire consequences allegedly facing our baby boom generation. The Times essay, by contributing opinion writer Anna Louie Sussman, is drawn from her forthcoming book “Inconceivable: The Impossibility of Family in an Age of Uncertainty.” In contrast to Ehrlich, whose predictions fortunately did not play out quite as catastrophically as he predicted, Sussman explores a different troubling situation, the declining birth rate among today’s rising generation of young couples. In April, the Centers for Disease Control and Prevention reported the nation’s general fertility rate had fallen to its lowest on record — down 1 percent from 2024 and down 23 percent from 2007. The fall in teenage fertility is even more stunning.…