For a few decades now, China has been converging with the U.S. economically.

Depending how you measure it, its gross domestic product has either already passed that of its great global rival or is getting ever closer. Average incomes are still much lower in China, but by another key metric of living standards, life expectancy, China matched the U.S. in the pandemic year of 2020.

As this century progresses, though, it appears that China will be experiencing economic convergence with the U.S. of another, less positive kind. The country’s working-age population of nearly a billion (defined here as those ages 15 through 64) has been essential to its economic rise, enabling it to become the workshop of the world and a vast consumer market.