The real population crisis confronting the world is depopulation, not overpopulation. A Review of Darrell Bricker and John Ibbitson’s Empty Planet.

Pamela J. Hobart studied philosophy and education at the doctoral level at Columbia University’s Teachers College, and she holds a B.A. magna cum laude in philosophy from Georgia State University. From 2012 to 2014, Pamela served as the K-12 Education Program Officer for the Institute of Humane Studies at George Mason University. Her research interests include virtue ethics, social norms, character education, homeschooling/​unschooling, and the epistemology of reasonable disagreement, and she lives in New York City.

It’s only natural to look around a dense neighborhood or at the traffic on a clogged highway and think, “Wow, there are way too many people on this planet already.” According to common sense, more people just means more problems: more people to feed and shelter, more pollution to harm the ecosystem, more people engaged in conflict and violence. If common sense is correct on this one, then reducing population numbers is in order. Several countries have responded to the perceived overpopulation crisis with top‐​down policies, like China’s morally and politically disastrous one‐​child policy. While those mandated policies are easy to condemn, are there downsides even to voluntary decreases in fertility, the cumulative effect of individual choices from the bottom‐​up?

As it so happens, common sense is wrong this time. The problem looming for humanity is one of too few people, not too many. The book Empty Planet: The Shock of Global Population Decline, by pollster Darrell Bricker and journalist John Ibbitson, addresses questions around human population in an empirically‐​grounded way. Bricker and Ibbitson warn that although “population decline isn’t a good thing or a bad thing … it is a big thing”. Even when the population level of a country begins to decrease voluntarily and gradually, the resulting sociocultural effects come on strongly and quickly.

Around the world, the same forces of urbanization, education, and female empowerment are shaping prospective parents’ expectations and hopes about their own future lives. Educated young urbanites regard childbearing as a project for personal fulfillment. Unlike their dwindling less‐​educated but more‐​rural counterparts, they do not produce a fleet of children out of duty to God or country or to serve as farmhands. There are almost no countervailing pressures to prop fertility up in the face of these trends.

First and foremost, population decline is a “big thing” for economic reasons. An ever‐​increasing population provides the basis for continuously increasing consumer demand: parents spend money on their children, and children grow up to become eager consumers too. A younger population also seems to keep a country’s business and technology climate innovative.

Closely related to those economic considerations are political ones. Young and old people are both highly dependent on others, but older people vote and form powerful special interest groups. When their needs begin to take precedence over those of children, society shifts in the direction of a self‐​fulfilling prophecy. As a society offers few daycare centers, schools, and other children’s amenities, adults find that bearing those children really does become even more difficult and expensive than before, and they reduce their fertility even further.

Bricker and Ibbitson point out that population decline has less tangible effects as well. The world’s languages are rapidly becoming extinct, both the cause and consequence of the declines of vibrant but small cultures (such as Gullah speakers living on the Sea Islands off the coast of South Carolina and Georgia). Although producing children isn’t guaranteed to be an adequate financial or social retirement plan, parents with only one or two children will face higher odds of loneliness toward the end of their lives, especially those who outlive their child or children.

So, significant decline in population would be detrimental if it were happening. Is it? Yes, the future is here; it’s just unevenly distributed. Some highly‐​developed countries such as Japan have already fallen into the “fertility trap,” the term for when the fertility rate falls below 1.5 children per woman and which causes a downward spiral in population. For the same mathematical reason that populations can grow quickly, they can shrink quickly too. However, the true scope of the decline is only just now becoming apparent.

Global population forecasts, notably the one produced by the United Nations’ World Population Prospects, tend to rely on the assumption that fertility rates (and, therefore, populations) will change in currently less‐​developed countries at the same pace as they already did in countries ahead of them on the development curve. Unfortunately, the past is an incompletely reliable guide to the future.

Instead, Bricker and Ibbitson find through their travels that fertility rates in countries such as China, India, and Brazil may very well be decreasing more quickly than they previously did in developed countries like the United States. If their findings are correct, world population will peak in just a few decades and then decline indefinitely. This scenario is much different from that in which the global population grows quickly towards infinity until our species implodes from overpopulation, the way a rotating cast of vocal agitators has long feared.

By the time population declines become permanent and the pattern is clear, it will be too late to reconfigure the math on social programs such as retiree pensions. Placing very high taxes on young people and parents, in a desperate attempt to make up the difference needed to fund such programs, will only further depress fertility. Although governments sometimes tinker at the margins with fertility‐​promoting programs such as child allowances, these policies are expensive and not typically very successful. If a force exists that can stem the tide of global population collapse, it hasn’t yet revealed itself.

All of this makes sense, as far as it goes. Bricker and Ibbitson have investigated this topic thoroughly, and they approach population decline in a rational, reasonable way (unlike the population explosion fearmongers). However, Bricker and Ibbitson’s Empty Planet has a hole in its argument: the carrying capacity of our planet.

If Earth simply cannot sustain as many humans as exist now (or will exist in the near future), then it doesn’t matter how otherwise beneficial it might be to have many families pushing up consumer demand or teaching their children obscure but interesting languages. Reality isn’t obligated to make life easy or pleasant for us. We might be merely quibbling over how quickly our species’ expiration date will arrive and over how much we’ll be able to consume in the relatively short meantime.

That’s not to say that the Earth’s carrying capacity is a fixed number. Instead, it depends heavily on available technologies, such as innovations boosting agricultural efficiency and methods for mitigating the effects of climate change. Humanity’s best bet at this point may be to reproduce as quickly as possible in the hope of creating a few scientific geniuses who can save us all. Fears that Earth will exceed its carrying capacity are not totally unreasonable, and they deserve to be addressed in an empirical way rather than casually brushed aside.

For now, let’s assume that the planet can sustain us all—“us” being the large (but smaller than previously predicted) human population of the near future. What ought to be done to ease population decline? What ought to be done to counterbalance its various harms?

Yet even that framing begs the question; saying we “ought” to do something about declining population assumes that we even can do something. Judging from various countries’ past experience, it seems that various social programs don’t actually work well to boost fertility rates (to the extent that they put a big dent in decline‐​related problems), so nothing ought to be done to boost them. This is especially true if society should default towards keeping governments out of personal family decisions on ethical grounds. The state may not be able to achieve perfect neutrality with respect to childbearing because it has to make choices on tax policy, public education, and so forth. But it can refrain from devising ad hoc, last‐​ditch efforts to throw money at potential parents to change their minds about childbearing.

Libertarians will notice that many of the problems of population decline that face developed countries can be—or previously could have been—avoided just by keeping the government in its proper place. Retirement funding schemes in developed countries would have been much less likely to collapse all at once if retirement planning had been treated as an individual financial responsibility and not as an entitlement program. Seniors wouldn’t have been able to collectively exercise an inappropriate amount of political power if there hadn’t been any tax‐​funded goodies at stake. It’s stressful to produce and raise children when families have high expectations for their children’s education, success, and material welfare. And zoning laws make it all the worse by inflating housing prices in desirable neighborhoods.

There is another way to populate a country, though, and Bricker and Ibbitson discuss the virtues of immigration at length in their book. When citizens don’t produce enough new people to fill up a country, existing people can be imported from elsewhere instead. Widespread immigration is likely to introduce changes to a country’s culture, but it is also likely to save the country’s balance sheet. Empty Planet explains in detail why the Canadian immigration model may be the way of the future: loose national identity coupled with deliberately‐​pursued, high levels of immigration (particularly for skilled immigrants).

A robustly libertarian society wouldn’t completely avoid whatever population‐​related problems are intrinsic to the forces of modernity. Still, less government involvement in people’s lives means that less can go wrong with that involvement. Unfortunately, as populations shrink, economies slow, and family trees wither, populist demands for state‐​provided support might just escalate. Already, political tensions have been reducing support for immigration exactly when more immigration would help the most. Ultimately, will politics solve the problems associated with population decline or will politics exacerbate them? I am not optimistic.

Check out our episode with John Ibbitson on Building Tomorrow here.