| By the end of this century, the global population will almost certainly start to shrink. Then it will keep shrinking until and unless something happens that has never happened for as long as reliable records have existed: Global birth rates will have to increase and stay there. Absent that, simple math dictates that the population eventually falls to zero. Depopulation is the subject of our latest Weekend Interview, in which my colleague Mishal Husain talks with political demographer Jennifer Sciubba. It’s also the topic of a recent book by economists Dean Spears and Michael Geruso, After the Spike: Population, Progress and the Case for People. Sciubba emphasizes the need to make institutions resilient to depopulation, while Spears and Geruso focus on stabilizing the global population without compromising gender equality. Despite the different framings, the three agree on a lot: that depopulation is coming later this century; that it will put massive pressure on economic, political and social systems; and that attempts to raise fertility historically often involved coercion and the repression of reproductive rights. They also agree that one of the most common policy responses — giving parents more money to make having kids more affordable — has only modest effects on population growth. “The evidence seems fairly clear that governments will not be able to quickly reverse fertility decline through modest cash transfers or incremental financial incentives,” write economists Melissa Kearney and Phillip Levine in a recent paper. They attribute lower fertility around the world to a shift in what people want from their lives rather than any narrow economic calculus. Another common theme is the need to share responsibility for caregiving — from men taking on more childcare to communities investing more in elder care. (After the Spike also dispatches with the idea that a shrinking population will rescue us from climate change: It will happen too late in the century.) “All of our assumptions about the way that the world works, theories we were taught about economic growth or development, they were formed in a time where we just assumed the population would continue growing,” Sciubba tells Husain. In the face of depopulation, she says those theories need rethinking. Spears and Geruso maintain that “it is not a solution to ask anyone to have more children than they want.” Rather, “it’s society’s collective task to lift the burdens of parents and other caretakers.” Sciubba’s 2022 book 8 Billion and Counting opens with a horrific attempt by Communist Romania to raise fertility by, among other measures, banning abortion. History suggests the first rule of considering depopulation is Do no harm. Spears and Geruso’s case centers on innovation: More people means more new ideas and bigger markets, which allow companies to spend more on upfront costs like research and development. A shrinking world would mean fewer innovators, and more problems that follow the economic logic of rare diseases, where a smaller market means less research is done to solve them. Whether or not societies buy into After the Spike’s case for stabilizing population, more and more countries around the world will likely switch from aging-but-growing to aging-and-shrinking over the next several decades — at least for a time. Discussion of aging economies often conclude that workers will have to stay in the labor force longer. If the goal is maintaining innovation, that may be particularly true in science and technology. But researchers have found that Nobel prize-winning scientists usually do their award-winning work before age 50, which suggests there’s no guarantee that just tacking on more years will lead to more breakthroughs. In a world where economies can’t count on population growth as a source of new ideas, they’ll need to somehow ensure that as we age we become more creative and inventive, not less. — Walter Frick, Bloomberg Weekend | 
