The human population can no longer be allowed to grow in the same old uncontrolled way. If we do not take charge of our population size, then nature will do it for us and it is the poor people of the world who will suffer most.
Over the observed range, people and good outcomes go hand in hand—and there’s no sign of anything else on the horizon.
You may have seen the satellite images of rainforest loss. You may have heard that we are in the middle of an anthropogenic extinction event. Perhaps you have become aware that a billion people are hungry and a sixth of the world lives in slums. Perhaps you have noticed that the costs of fuel and food continue to rise dramatically, trends that have historically been followed by large-scale misery and mass human die-offs.
Bryan Caplan sees a clear solution to all these troubling problems: more babies.
Characterizing population worries like those of David Attenborough, above, as "fretting," Caplan surprisingly argues that increasing population has always gone along with greater human well-being, and that there is every reason to suspect that a larger population will result in higher levels of human welfare in the future.
With a totally straight face.
Lest you suspect I am mischaracterizing Caplan's argument for dramatic effect, here are some direct quotations:
People have been fretting about the “population problem” for at least fifty years. But over those five decades, the perceived problem has practically reversed.
During the last two centuries, both population and prosperity exploded. Maybe the world just enjoyed incredibly good luck, but it makes you wonder: Could rising population be a cause of rising prosperity?
When population goes up, everyone gets extra choices. [Emphasis in original.]
And the only mention of environmental problems at all in the entire essay:
After two centuries of rising population and rising prosperity, attempts to blame low living standards on overpopulation have worn thin. The most popular anti-population arguments now come from environmentalists. But their case is surprisingly weak. We’re not “running out” of food, fuel, or minerals. Despite occasional price spikes, real commodity prices have fallen about 1% per year for over a century. Air and water quality in the First World have been improving for decades despite rising population. Genuine problems remain, but limiting population to counter environmental problems is using a sword to kill a mosquito. Pollution taxes and congestion prices are far cheaper and more humane remedies. [Citations omitted.]
Caplan argues, essentially, that (a) ideas come from human brains; (b) ideas drive prosperity; (c) more brains mean more ideas. He maintains that there is no downside to growing population; somehow, all those new brains will come up with ideas that will solve all of our present problems, and all future problems as well.
At its core, Caplan's argument is that we should ignore direct, certain harms and costs of rising population (environmental destruction, water shortages, overpopulation-driven conflicts like the Rwandan genocide) and focus on the indirect, uncertain potential future benefits of increasing population - all those ideas future brains might come up with.
Optimism is not nice (or "humane") when it allows for the mental elision of real human suffering. More importantly, it is not warranted when the harms are direct and certain and the benefits are indirect and uncertain.
"Imagine deleting half the names in your music collection—or half the visionaries in the computer industry," says Caplan. "Think how much poorer the world would be." He includes a sentimental quotation from fellow breeding advocate Julian Simon, who says:
There came to me the memory of reading a eulogy delivered by a Jewish chaplain over the dead on the battlefield at Iwo Jima, saying something like, “How many who would have been a Mozart or a Michelangelo or an Einstein have we buried here?” And then I thought, Have I gone crazy? What business do I have trying to help arrange it that fewer human beings will be born, each one of whom might be a Mozart or a Michelangelo or an Einstein—or simply a joy to his or her family and community, and a person who will enjoy life?
The idea that we should breed lots more people because there might be a Mozart or an Einstein among them has two major problems. One is that the sheer number of brains is not the sole determinant of the creation of valuable ideas - else the slums of São Paulo would be outperforming Cambridge, Massachusetts, in new idea creation. (And these other determinants of the creation of valuable ideas, tied as they often are to real-world, material resources, may very well be negatively affected by increased population.) Another is that at the outset, the creation of a new Josef Fritzl is at least as likely as the creation of a new Einstein. (Indeed, many people who have committed horrific crimes fit the definition of the type of person Caplan says we should make more of - people whose lifetime tax payments exceed their lifetime consumption of government services. Even Jeffrey Dahmer, killed so quickly after his incarceration, might have met these criteria.)
Caplan is correct that each new person is a potential cooperation partner for every existing person. But he ignores the fact that each new person is also a new competitor. Caplan makes much of the fact that "much" government spending is "non-rival" - that is, it doesn't increase with population size. But how much of human welfare is truly "non-rival"? It is an undeniable fact that humans compete for resources that are genuinely scarce, such as water and land. This could be solved, in Caplan's magical view, by new ideas.
Caplan thinks reducing population to reduce harms like scarcity and environmental destruction is "like using a sword to kill a mosquito." In my view, breeding lots of new people in hopes that they come up with solutions to the problems caused by overpopulation is akin to snorting cocaine in hopes that it helps you figure out a way to overcome your cocaine addiction.
Or, perhaps more poignantly, it's like open-pit-mining the fuck out of Montana in hopes that microorganisms in the digestive tracts of endangered snow geese that die horribly in the polluted open pits will prove capable of cleaning up the damage.