The Birth Dearth: Panic or Celebrate?

Where have all the babies gone? In more than half the countries in the world, the United States included, women are no longer having enough children to hold population steady. As a result, we are on the brink of a dramatic shift from a growing to a declining global population.

To be sure, when we look at the whole long history of humanity, steady population growth has been anything but the norm. For the first 100,000 years or so, periods of growth were punctuated by big dips, like those caused by global cooling following the Toba volcano eruption 70,000 years ago, or the Black Death pandemic of the 14^th century. But by 1800, the number of humans on the planet had reached a billion people, and the next couple of centuries brought us to 8 billion.

Now, seemingly suddenly, the end of population growth is in sight. Projections vary, but most demographers expect average human fertility to drop below the replacement rate by mid-century. Once that happens, there will be only a short lag before population begins a gradual decline stretching into the indefinite future.

Many observers contemplate the falling population with dread. Elon Musk calls it a “bigger risk to global civilization than global warming.” Others see lower population growth as a boon. So, should we panic, or celebrate? Take a closer look at three issues divide population pessimists from optimists: economics, geopolitics, and quality of life.

The Models

On the economic front, the pessimists often point to elegant mathematical models such as one by Stanford economist Charles Jones. Jones argues that without perpetually growing numbers of people working on problems together and ever more firms competing with one another, innovation will slow to a crawl. Without innovation, living standards will gradually stagnate until the last living humans sadly bequeath an empty planet to the weeds and the bugs.

But let’s remember, these are only models. As Erica Thompson explains in her book Escape from Model Land (required reading for every social scientist!), models are useful, but they are only metaphors tarted up with fancy math. We should not ask whether models are right or wrong, but only whether they are suitable for a given purpose. “While our models can predict, warn, motivate, or inspire,” she writes, “we must ourselves navigate the real-world territory and live up to the challenge of making the best of our imperfect knowledge to create a future worth living in.”

The population-impact models produce sound conclusions so long as we keep their “other things being equal” assumptions in mind. However, they omit many messy variables and self-corrective feedbacks that are likely to offset any decline in living standards as the population falls. For example, as an aging population puts pressure on labor markets, wages and workforce participation rates are likely to rise, both among the population traditionally considered to be “of working age” and among older individuals. More educated workers, who tend to be more productive, are more likely to stay on the job into their late sixties and beyond. Also, since fertility is a heritable trait, groups inclined toward higher fertility are likely to increase as a share of the population as total headcount falls.

And even if we ignore these countervailing effects, the rate of growth of per capita income is likely to slow only gradually. Jones, for example, estimates that it would take from 85 to 250 years, depending on which variation of his model you choose, for the rate of growth of productivity (about 0.6 percent per year since 2000) to fall to half of its current value. Compared to threats like climate change, pandemics, and nuclear war, that does not see too scary.

Geopolitics

While economists tend to think in terms of per capita income, which can continue to grow even as population falls, geopolitical analysts generally look to total GDP for a country’s ability to project power in the world. See, for example, this one by retired CIA officer Harry Hannah, who worries  about building “national power to compete with China.”

The argument is superficially plausible, but population is only one among many factors determining power in geopolitical competition. Alliances, trade, and quality of governance also matter, as do diplomatic and military strategy. The United States outcompeted the Soviet Union during the cold war despite having a smaller population. Similarly, it is hard to argue that America’s geopolitical stumbles in Vietnam, Iraq, and Afghanistan were primarily a result of insufficient U.S. population.

On top of that, it is worth noting that strategic competitors China and Russia are already experiencing even more rapid declines in reproduction than the United States. Trends in inward and outward migration are also more favorable to the United States (more on that shortly).

Quality of life

We can quantify the economic and geopolitical effects of falling population, but effects on quality of life are more subjective. Quantifiable or not, though, they play a role in the gloomy scenarios spun by some population pessimists.

The Economist, for example, paints a dismal picture of towns like Cairo, Illinois, a bustling river port with 15,000 inhabitants in the 1920s but now a ghost town with barely a tenth of its former population. Even though many who deserted the town (and their descendants) are happy elsewhere, the lives of those unwilling or unable to move have gotten worse as their neighbors have left.

Others point to what they see as the inherent lifestyle advantages of population density. Commentator Matthew Yglesias waxes eloquent about specialty chess stores that can be found only in ultra-dense cities like New York. He notes that restaurants catering to diverse tastes and all learning from one another are better where you have a high density of customers, workers, and owners. He agrees that social media and Zoom chats are nice but insists that face-to-face interactions with real people allow you to learn things that you cannot learn through a screen. 

Having lived for many years in densely populated cities on three continents, I agree that all those things are good. Still, I prefer the other half of my life that I have spent in small-town America. On balance, small towns offer lifestyle advantages of their own that I find even more attractive than those of the megalopolis. Clean air. Dark skies. Quiet. Daily contact with diverse plant and animal life. Free, uncrowded town tennis courts. Local groups for singing, games, political discussion or whatever your passion is – they may seem irritably amateurish to urbanites, but they suit my taste. And while it is true that some American small towns like Cairo have descended into death spirals, others are thriving.

Along with the micro-level advantages of low density, there are macro benefits, too. Writing that aging human populations are good for us and good for the earth, Frank Götmark (Sweden), Philip Cafaro (USA), and Jane O’Sullivan (Australia) point to lower greenhouse gas emissions as one such benefit. Proponents of continued population growth like economics blogger Noah Smith note that “with the advent of cheap green energy, we now have the means to address that problem,” but the effects on habitat and biodiversity of more people eating more food, expanding into wilderness, digging more mines and operating more factories are harder to offset.

Why can’t we just boost fertility?

Even if the downsides of falling fertility are exaggerated and the benefits understated, wouldn’t adjustment be easier if we could slow down the rate of decrease a bit? Perhaps that would not be a big problem for the United States, where fertility is currently only a little below the replacement rate. But think about countries like South Korea and China, where each succeeding generation is on track to be just half as large as the one preceding it – maybe even smaller.

Not surprisingly, many countries have responded to the birth dearth with cash bonuses for babies, generous parental leave, subsidized childcare, and other incentives. But study after study has concluded that such policies have little if any effect. Economist Elizabeth Brainerd of Brandeis University concludes that  “Pronatalist government policies can increase fertility rates modestly, but they are unlikely to move fertility rates up to replacement levels.”

One problem is that pronatalist policies are dauntingly costly, since bonuses, subsidies, and tax breaks tend to go to all parents, including the majority who would choose to have just as many children even without them. In countries such as Poland and France, where such policies have had small but measurable effects, the cost is said to have been $1 million or more per added birth.

Another point to note is that most of the decline in fertility over recent decades, at least in developed countries, has been among younger women. In the United States, over half of the decrease is due to fewer teen pregnancies – something to welcome on grounds of social policy. Persuading older and better educated women to have more children is much harder. Their incomes are higher, so a bonus of a few thousand dollars is less likely to change their family and professional plans. And research suggests that women -- and sometimes their doctors, too -- tend to underestimate the decline in their own fertility when they do finally try to start a family.

Finally, even if effective, how far would we really want to go in bribing or even coercing women to have more babies? Vladimir Putin has taken to urging women to forego education and careers in order to prioritize children. Chinese officials are reportedly going door to door to monitor women’s reproductive status. Even in our own country, the attorneys general of Idaho, Kansas and Missouri have argued in court that access to abortion pills is “causing a loss in potential population or potential population increase,” and that “decreased births” were inflicting “a sovereign injury to the state itself.” Is that really the way we want to go?

Nor is immigration a magic bullet

Immigration is another potential social policy lever for easing the transition. The concept is simple. In a country with fertility below the replacement rate, the birth cohorts entering working age are smaller than those entering retirement age. That raises the dependency ratio – the number of mouths per pair of working hands. By lowering the dependency ratio, working-age immigrants can help boost real output and provide the tax revenues needed to provide social services to seniors.

In practice, though, it is hard to get the math to work out. It takes more immigrants than one might think to make much of a dent in the dependency ratio, now about 39.7 dependents per 100 workers.

The U.S. Census Bureau makes population projections for various immigration scenarios. The baseline projection, using current rates of immigration, projects that between 2022 and 2060, the U.S. population will grow from 333 million to 364 million, while the dependency ratio will rise to 42 percent. In a high-immigration scenario (half-again higher than now), total population will grow to 397 million and the dependency ratio will be fractionally lower, at 41.5 percent. In a hypothetical zero-immigration scenario, total population would fall to 299 million and while the dependency ratio would rise to 43.4 percent.

Comparing the zero-immigration scenario to the one for high immigration, then, it turns out that adding 98 million people to the population through immigration – a three-fold increase over the current rate – would cut the dependency ratio by less than two percentage points. A welcome increase, perhaps, but hardly a game-changer.

Then there’s the issue of politics. Even though many Americans take pride in their country as a nation of immigrants, there are limits to the willingness to welcome more – as the last presidential election seems to confirm. According to a 2024 Gallup poll, 35 percent of Americans are satisfied with the current rate of immigration, 55 percent would like to see fewer immigrants, and just 16 percent are open to an increase. When we consider both the mathematical and political realities, then, depending on accelerated immigration to fully stabilize the dependency ratio seems unrealistic.

Change what we can, accept what we can’t

A well-known prayer urges us to change what we can, accept what we can’t, and be wise enough to know the difference. In a secular context, that advice applies perfectly to how we should think about the birth dearth.

What we cannot change is the world-wide trend toward lower fertility. Many countries have tried to reverse the trend with pronatalist incentives, but the results have been modest at best. Success is doubtful for even the most authoritarian measures.

On the positive side, there are good reasons why it would not only be wise to accept lower fertility as inevitable, but to embrace it. We should celebrate the main causes – empowerment of women, better education, higher incomes, and lower mortality at both ends of the human lifespan – for their own sake. At the same time, we should welcome the environmental benefits of lower human populations. Falling population is not a “curse of riches” we should fight against. As Götmark, Cafaro, and Sullivan put it, it is “an achievement misdescribed as a problem.”

Americans can be thankful that we have at least a little room to maneuver. Our 2023 total fertility rate of 1.62 expected children per woman is below the replacement level (about 2.1), but not even close to the world’s lowest (South Korea and Hong Kong are both below 1.)  America’s popularity as a destination for immigrants is another plus, giving us some discretion to choose the most productive. In order not to squander these advantages, we need to adapt, not to fight reality.

Writing in Foreign Affairs, Nicholas Eberstadt of the American Enterprise Institute points out that the same formula that built today’s prosperity in the past can help us meet the challenges of a future world marked by depopulation. “The essence of modern economic development,” he points out, “is the continuing augmentation of human potential and a propitious business climate, framed by policies and institutions that help unlock the value in human beings.” Better education. Better healthcare. A stronger social safety net. All these are worth undertaking on their own merits and will ease the transition, even if they have only small effects on fertility.

First published in Milken Institute Review, May 2, 2025. Reposted with Permission. Photo courtesy of  Pixabay.com.