Space, the Ultimate in Family Planning

I would hope fears about global overpopulation don’t live beyond Paul “The Population Bomb” Ehrlich, who passed away in March. Still, pockets of people who haven’t updated their priors on the population issue in decades almost certainly remain. For such holdouts, I recommend a short and sharp new analysis from the St. Louis Fed, in which economists B. Ravikumar and Guillaume Vandenbroucke point out that “birth rates have fallen steadily in both rich and poor countries, with the gap between the top and bottom quintiles of nations—ranked by GDP per capita—narrowing from 2.4 percentage points in 1960 to 0.9 percentage points in 2023.” In other words, everyone is headed in the same direction on fertility. And there doesn’t seem to be much policymakers can do about it. Ravikumar and Vandenbroucke cite a Harvard Magazine article summarizing a 2025 panel that examined the falling American birth rate and found the available policy tools weak, with only modest effects—a conclusion well within the economic mainstream. What I found particularly interesting about the St. Louis Fed piece was the counterfactual it presented. Hold birth rates at their 1960 levels and the world today would have roughly 3.4 billion more people, almost all of them in the poorest countries. Rich countries would have added only about 400 million. This is very much like the scenario that Ehrlich and other population worriers back then imagined. Their response was that humanity needed radical reorganization: fewer people using far fewer resources. But one could accept the “limits to growth” thesis and still offer a pro-progress response. Gerard O’Neill, a Princeton physicist who in the 1970s designed vast spinning space habitats capable of housing millions, would have found that counterfactual—a planet groaning under three-plus billion additional souls—to be well within his expectations, as I noted in a recent newsletter essay. In that way, he was a man of his time. But not entirely. Whereas the neo-Malthusians’ preferred option was a globally managed steady-state society, O’Neill turned his eyes to the skies. Scarcity, in his reading, was merely a geography problem. Move heavy industry off-planet, mine the asteroid belt, build those space cylinders at Lagrange points , and suddenly a few billion extra humans become a civilizational asset. The steady-state alternative, he added, would require coercion on a scale indistinguishable from dystopia. O’Neill preferred abundance engineered through ingenuity. Were O’Neill’s ideas realistic? He thought the basic science and technology already existed. And even if he was premature—we now know, by the way, that it is possible to radically reduce launch costs thanks to Elon Musk and SpaceX—one could imagine a crash program to make his vision a reality. Certainly, that vision was more appealing (and I think workable) than the degrowth alternative. Imagine America at 250 had we pursued it. The post Space, the Ultimate in Family Planning appeared first on American Enterprise Institute - AEI .