Wednesday, July 20, 2011

Population Is Magic

Does a future of glorious prosperity await us if we forget about the direct, measurable harms of overpopulation and instead focus on the indirect, unpredictable benefits that might come from denser populations?

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.
David Attenborough
Over the observed range, people and good outcomes go hand in hand—and there’s no sign of anything else on the horizon.
Bryan Caplan

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.


  1. Agreed, Bryan Caplan is a complete psychopath.

    For anyone with scientific know how to take his position is criminal.

  2. I'll save the details of my mixed assessment of Bryan Caplan for another time (executive summary: brilliant and inventive social scientist, moral philosophy idiot) and note that pollyannaism about population growth is not limited to him. It crops up in other libertarian-leaning economists, like Steven Landsburg,, for example.

  3. I think it should be fairly obvious that the population rose so much because of improving technology. Deliveries became safer, and infant mortality rate was brought down. Also, probably, society became more monogamic, giving EVERYONE the chance to marry and have kids. It's almost celebrated as a universal right now.

  4. I've generally observed that those who deny the problems of overpopulation are well-heeled, overpaid, sheltered academics who would no more live in a crowded tenement block or work in a low-paid job to save their lives.

  5. If I deleted half the names in my music collection, the blank spaces would quickly be filled in by all the brilliant musicians who escaped my (and most people's) notice to die in obscurity under the population avalanche. Dickbag.

  6. (...but really, isn't all that human suffering worth it so he can have that kick-ass Kenny Loggins CD? If ya wanna make an omelette...)

  7. People like Caplan are so sure that more new lives are better than fewer new lives, that they don't even require what would normally be considered minimal standards of evidence to back up their claims. If the only data we have are from rapidly growing populations, it's pretty hard to confidently make claims about the QoL of counterfactual populations that had significantly slower (possibly 0 or negative) growth rates. Imagine if from the beginning of recorded history everyone had been given a drug, and then we attributed economic growth to that drug.

  8. I wouldn't bet against short-term optimists on most metrics (though indefinite-term optimism flies in the face of physics, as I suspect even Caplan would admit if sufficiently challenged). There are reasonable grounds for believing (or speculating) that the trends celebrated by Caplan -- and Simon before him -- will continue for some time, that income and living standards and even, I suspect, the price of farmland will continue to improve in relative terms throughout our lives. Notwithstanding your deeper economic objections concerning revealed preference and negative value, I think Bryan is correct to identify human ingenuity -- and markets -- as driving forces behind relative improvements in human welfare over the past few hundred years, and I further suspect that the Malthus-defying trendlines will continue apace, long enough for him to collect on his wagers. The main difference between my profoundly qualified optimism and Caplan's starry-eyed optimism is that I recognize that more people, whatever benefits they (some of them) may bestow for the general rising population, inevitably means more people who will suffer, in many cases horribly. Population growth, by any metric, cannot change this obdurate reality.

    Of course, Caplan has made it clear that this is (for him) a non-issue, since he asserts, without ever disdaining to meet antinatalist objections, that "life is a gift" -- even if some lives are marked by terrible pain, even if all lives are doomed to the same thudding fate. So, given that my ultimate objection is a non-starter, I would amplify one of your main points, which is that Caplan -- who really does know better, given his Judith-Rich-Harris-approved contrarian stance vis-a-vis the endless debate over environment and nature -- is playing fast and loose when he argues that population as such is a reliable predictor of future innovation. The birth of Einstein (whose big idea might still destroy the world) wasn't a population-dependent chance event like a sequence of lottery numbers; Einstein's talents, like everyone's, owed to cultural and biological factors that cannot be duplicated by mere addition. Quantity is not quality, especially in a game where human aptitude is key. Given his soft bio-realist cred, I suspect that Caplan is being disingenuous when he imputes a simple causal relationship between more and better. This is too bad when you consider that population growth tends to be high in places where grave human suffering is most pronounced.

  9. Chip,

    Income, living standards and price of farmland!

    The problem is, not having a mobile phone today can be as depriving as having no legs earlier. And it may just not be psychological.

    As the population grew, correspondences were pushed farther and farther away from each other, and they began needing fuel and the vehicles it runs to pay visits.

    They keep saying India has surplus grain -- but to move the grain around you also need fuel. Do we have enough of THAT? Oh, and I forgot roads.

  10. Sister Y, thank you very much for posting this link. I am going to rip this guy a new asshole as well. You do know he is an avowed natalist who wrote a book about it, right?

    Also, CATO Institute is one of those fake libertarian organizations that actually promote capitalism. It was founded by one of the Koch brothers. They are part of the enemy ranks, honestly.

  11. "all those new brains will come up with ideas that will solve all of our present problems, and all future problems as well."

    A problem I see here is that it is plausible enough that given current rates of progress the brains that already exist on this planet are capable of solving these problems without new help, and the lag between birth and capacity for innovation is a minimum of two decades.

  12. Will? Someone is counting their chickens before they hatch.


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