If during his last days American biologist Paul Ehrlich had followed events in Singapore, he would have heard something remarkable. Fertility fell to a record low last year, confounding efforts to shore it up. Politicians described the development as an existential challenge.

Ehrlich, who saw population control as vital to humanity’s viability amid a deteriorating environment, was proven wrong. Not only is humankind doing pretty well, leaders in some of the most successful economies want the opposite of what the Stanford University professor prescribed: more babies. China, South Korea, Japan and many European nations are wrestling with ultralow birthrates and shrinking labor markets. Combined with the swelling ranks of seniors, these forces promise to reshape workplaces, tax systems, immigration and defense.

This isn't the world that Ehrlich, who died on March 13, envisaged when he published "The Population Bomb" in 1968. The book was a smash hit and the author's frequent appearances at conferences and on television did much to propagate the idea that many of the world's most pressing difficulties could be addressed by clamping down hard on headcount. It might even be too late, he wrote, to avoid apocalyptic outcomes: mass famine, plagues, world wars resulting from food shortages and pollution so severe that it would be a battle to survive.

© The Japan Times