The Census Bureau’s latest numbers show that these trends are catching up with us. As of April 1, it reports that there were 331,449,281 residents in the United States, an increase of just 7.4 percent since 2010 — the second-smallest decade-long growth rate ever recorded, only slightly ahead of the 7.3 percent growth during the Depression-struck 1930s.
The bureau projects that sometime next decade — that is, in the 2030s — Americans over 65 will outnumber Americans younger than 18 for the first time in our history. The nation will cross the 400-million population mark sometime in the late 2050s, but by then we’ll be quite long in the tooth — about half of Americans will be over 45, and one fifth will be older than 85.
The idea that more people will lead to greater prosperity may sound counterintuitive — wouldn’t more people just consume more of our scarce resources? Human history generally refutes this simple intuition. Because more people usually make for more workers, more companies, and most fundamentally, more new ideas for pushing humanity forward, economic studies suggest that population growth is often an important catalyst of economic growth.
A declining global population might be beneficial in some ways; fewer people would most likely mean less carbon emission, for example — though less than you might think, since leading climate models already assume slowing population growth over the coming century. And a declining population could be catastrophic in other ways. In a recent paper, Chad Jones, an economist at Stanford, argues that a global population decline could reduce the fundamental innovativeness of humankind. The theory is simple: Without enough people, the font of new ideas dries up, Jones argues; without new ideas, progress could be imperiled.
There are more direct ways that slow growth can hurt us. As a country’s population grows heavy with retiring older people and light with working younger people, you get a problem of too many eaters and too few cooks. Programs for seniors like Social Security and Medicare may suffer as they become dependent on ever-fewer working taxpayers for funding. Another problem is the lack of people to do all the work. For instance, experts predict a major shortage of health care workers, especially home care workers, who will be needed to help the aging nation.
Pundits are fond of putting forward grand, unattainable proposals for reviving America: Matthew Yglesias’s proposal that we should aim for one billion Americans, for example, or my fanciful argument in favor of open borders. But to stave off the worst effects of slowing growth, we don’t need to smash open the borders and let in the whole world. All we have to do is become the same welcoming nation we once were.
In a recent report, Ali Noorani, the chief executive of the National Immigration Forum, an immigration-advocacy group, and a co-author, Danilo Zak, say that increasing legal immigration by slightly more than a third each year would keep America’s ratio of working young people to retired old people stable over the next four decades. The Census Bureau projected that the United States would welcome about one million legal immigrants in 2020; under Noorani’s proposal, that number would be 1.37 million people. Is that a lot? Not by historical standards. According to figures compiled by the Cato Institute’s David Bier, since the Revolutionary War in 1783, the United States’ average annual rate of legal immigration has been about 0.4 percent of the population. For our current population, that would amount to about 1.33 million people, pretty close to Noorani’s proposal.