The Global Fertility Crash

As birthrates fall, countries will be forced to adapt or fall behind.

- Andre Tartar, Hannah Recht, and Yue Qiu

At least two children per woman—that’s what it takes to ensure a stable population from generation to generation. In the 1960s, the fertility rate was five live births per woman; by 2017 it had fallen to 2.43, close to that critical threshold.

Population growth is vital for the world economy. It means more workers to build homes and produce goods, more consumers to buy things and spark innovation, and more citizens to pay taxes and attract trade. While the world is expected to add more than 3 billion people by 2100, according to the United Nations, that’ll likely be the high point. Well before then, falling fertility rates and aging populations will become serious challenges— challenges that will be felt more acutely in some places than others. While the global average fertility rate was still above the rate of replacement— technically, 2.1 children per woman— in 2017, about half of all countries had already dropped below it, compared with 1 in 20 just half a century ago.

Population dynamics needn’t be economic destiny. A study last year by the Organization for Economic Cooperation and Development found that, for most major economies, rising productivity was a more important driver of gross domestic product growth from 2000 to 2017 on average than population growth or change in the employment rate. That may not be sustainable over time, however: For most countries in the OECD study, the relative contribution of productivity to growth has fallen over time. In some countries, too-high fertility may actually be a drag on GDP because of higher costs.