When I was born near the Baby Boom’s peak, many people worried that the population was growing too fast. Today, the shoe is on the other foot. All over the world, birth rates have collapsed, and we face the prospect of a shrinking population. Over two-thirds of the world’s population lives in countries with birth rates below replacement, including India, China, the U.S., Brazil, and all of Europe. The United Nations projects that the global population will peak near the end of the century, but many demographers now expect that to occur much sooner—perhaps as early as 2050.

People who see the declining population as a good thing tend to ignore the difficulties it will create. Let’s begin with the fiscal havoc. The federal government continues to spend more than it taxes, causing its debt to spiral upward.