The Age of Depopulation: Surviving a World Gone Grey

Although few yet see it coming, humans are about to enter a new era of history. Call it “the age of depopulation.” For the first time since the Black Death in the 1300s, the planetary population will decline. But whereas the last implosion was caused by a deadly disease borne by fleas, the coming one will be entirely due to choices made by people.

With birthrates plummeting, more and more societies are heading into an era of pervasive and indefinite depopulation, one that will eventually encompass the whole planet. What lies ahead is a world made up of shrinking and ageing societies. Net mortality—when a society experiences more deaths than births—will likewise become the new norm. Driven by an unrelenting collapse in fertility, family structures and living arrangements heretofore imagined only in science fiction novels will become commonplace, unremarkable features of everyday life.
Human beings have no collective memory of depopulation. Overall global numbers last declined about 700 years ago, in the wake of the bubonic plague that tore through much of Eurasia. In the following seven centuries, the world’s population surged almost 20-fold. And just over the past century, the human population has quadrupled.

The last global depopulation was reversed by procreative power once the Black Death ran its course. This time around, a dearth of procreative power is the cause of humanity’s dwindling numbers, a first in the history of the species. A revolutionary force drives the impending depopulation: a worldwide reduction in the desire for children.

So far, government attempts to incentivise childbearing have failed to bring fertility rates back to replacement levels. Future government policy, regardless of its ambition, will not stave off depopulation. The shrinking of the world’s population is all but inevitable. Societies will have fewer workers, entrepreneurs, and innovators—and more people dependent on care and assistance. The problems this dynamic raises, however, are not necessarily tantamount to a catastrophe. Depopulation is not a grave sentence; rather, it is a difficult new context, one in which countries can still find ways to thrive. Governments must prepare their societies now to meet the social and economic challenges of an ageing and depopulating world.

In the United States and elsewhere, thinkers and policymakers are not ready for this new demographic order. Most people cannot comprehend the coming changes or imagine how prolonged depopulation will recast societies, economies, and power politics. But it is not too late for leaders to reckon with the seemingly unstoppable force of depopulation and help their countries succeed in a world gone grey.

A Spin of The Globe

Global fertility has plunged since the population explosion in the 1960s. For over two generations, the world’s average childbearing levels have headed relentlessly downward, as one country after another joined in the decline. According to the UN Population Division, the total fertility rate for the planet was only half as high in 2015 as it was in 1965. By the UNPD’s reckoning, every country saw birthrates drop over that period.

And the downswing in fertility just kept going. Today, the great majority of the world’s people live in countries with below-replacement fertility levels, patterns inherently incapable of sustaining long-term population stability. (As a rule of thumb, a total fertility rate of 2.1 births per woman approximates the replacement threshold in affluent countries with high life expectancy—but the replacement level is somewhat higher in countries with lower life expectancy or marked imbalances in the ratio of baby boys to baby girls.)

In recent years, the birth plunge has not only continued but also seemingly quickened. According to the UNPD, at least two-thirds of the world’s population lived in sub-replacement countries in 2019, on the eve of the COVID-19 pandemic. The economist Jesús Fernández-Villaverde has contended that the overall global fertility rate may have dropped below the replacement level since then. Rich and poor countries alike have witnessed record-breaking, jaw-dropping collapses in fertility. A quick spin of the globe offers a startling picture.

Start with East Asia. The UNPD has reported that the entire region tipped into depopulation in 2021. By 2022, every major population there—in China, Japan, South Korea, and Taiwan—was shrinking. By 2023, fertility levels were 40 percent below replacement in Japan, over 50 percent below replacement in China, almost 60 percent below replacement in Taiwan, and an astonishing 65 percent below replacement in South Korea.

As for Southeast Asia, the UNPD has estimated that the region as a whole fell below the replacement level around 2018. Brunei, Malaysia, Singapore, and Vietnam have been sub-replacement countries for years. Indonesia, the fourth most populous country in the world, joined the sub-replacement club in 2022, according to official figures. The Philippines now reports just 1.9 births per woman. The birthrate of impoverished, war-riven Myanmar is below replacement, too. In Thailand, deaths now exceed births and the population is declining.

In South Asia, sub-replacement fertility prevails not only in India—now the world’s most populous country—but also in Nepal and Sri Lanka; all three dropped below replacement before the pandemic. (Bangladesh is on the verge of falling below the replacement threshold.) In India, urban fertility levels have dropped markedly. In the vast metropolis of Kolkata, for instance, state health officials reported in 2021 that the fertility rate was down to an amazing one birth per woman, less than half the replacement level and lower than in any major city in Germany or Italy.

The UNPD has estimated that the replacement threshold for the world as a whole is roughly 2.18 births per woman. Its latest medium variant projections—roughly, the median of projected outcomes—for 2024 have put global fertility at just three percent above replacement, and its low variant projections—the lower end of projected outcomes—have estimated that the planet is already eight percent below that level. It is possible that humanity has dropped below the planetary net-replacement rate already. What is certain, however, is that for a quarter of the world, population decline is already underway, and the rest of the world is on course to follow those pioneers into the depopulation that lies ahead.

The Power of Choice

The worldwide plunge in fertility levels is still in many ways a mystery. It is generally believed that economic growth and material progress—what scholars often call “development” or “modernisation”—account for the world’s slide into super-low birthrates and national population decline. Since birthrate declines commenced with the socioeconomic rise of the West—and since the planet is becoming ever richer, healthier, more educated, and more urbanised—many observers presume lower birthrates are simply the direct consequence of material advances.

But the truth is that developmental thresholds for below-replacement fertility have been falling over time. Nowadays, countries can veer into sub-replacement with low incomes, limited levels of education, little urbanisation, and extreme poverty. Myanmar and Nepal are impoverished UN-designated Least Developed Countries, but they are now also sub-replacement societies.

During the postwar period, a veritable library of research has been published on factors that might explain the decline in fertility that picked up pace in the twentieth century. Drops in infant mortality rates, greater access to modern contraception, higher rates of education and literacy, increases in female labour-force participation and the status of women—all these potential determinants and many more were extensively scrutinised by scholars. But stubborn real-life exceptions always prevented the formation of any ironclad socioeconomic generalisation about fertility decline.

Eventually, in 1994, the economist Lant Pritchett discovered the most powerful national fertility predictor ever detected. That decisive factor turned out to be simple: what women want. Because survey data conventionally focus on female fertility preferences, not those of their husbands or partners, scholars know much more about women’s desire for children than men’s. Pritchett determined that there is an almost one-to-one correspondence around the world between national fertility levels and the number of babies women say they want to have. This finding underscored the central role of volition—of human agency—in fertility patterns.
Volition is why, even in an increasingly healthy and prosperous world of over eight billion people, the extinction of every family line could be only one generation away.

Countries for Old Men

The consensus among demographic authorities today is that the global population will peak later this century and then start to decline. Some estimates suggest that this might happen as soon as 2053, others as late as the 2070s or 2080s.

Regardless of when this turn commences, a depopulated future will differ sharply from the present. Low fertility rates mean that annual deaths will exceed annual births in more countries and by widening margins over the coming generation. According to some projections, by 2050, over 130 countries across the planet will be part of the growing net-mortality zone—an area encompassing about five-eighths of the world’s projected population. Net-mortality countries will emerge in sub-Saharan Africa by 2050, starting with South Africa. Once a society has entered net mortality, only continued and ever-increasing immigration can stave off long-term population decline.

Future labour forces will shrink around the world because of the spread of sub-national cohorts of people between the ages of 15 and 49 will decrease more or less everywhere outside sub-Saharan Africa. That group is already shrinking in the West and in East Asia. It is set to start dropping in Latin America by 2033 and will do so just a few years later in Southeast Asia (2034), India (2036), and Bangladesh (2043). By 2050, two-thirds of people around the world could see working-age populations (people between the ages of 20 and 64) diminish in their countries—a trend that stands to constrain economic potential in those countries in the absence of innovative adjustments and countermeasures.

A depopulating world will be an ageing one. Across the globe, the march to low fertility, and now to super-low birth rates, is creating top-heavy population pyramids, in which the old begin to outnumber the young. Over the coming generation, aged societies will become the norm.

By 2040—except, once again, in sub-Saharan Africa—the number of people under the age of 50 will decline. By 2050, there will be hundreds of millions fewer people under the age of 60 outside sub-Saharan Africa than there are today—some 13 per cent fewer, according to several UNPD projections. At the same time, the number of people who are 65 or older will be exploding: a consequence of relatively high birth rates back in the late twentieth century and longer life expectancy.

While overall population growth slumps, the number of seniors (defined here as people aged 65 or older) will surge exponentially—everywhere. Outside Africa, that group will double in size to 1.4 billion by 2050. The upsurge in the 80-plus population—the “super-old”—will be even more rapid. That contingent will nearly triple in the non-African world, leaping to roughly 425 million by 2050. Just over two decades ago, fewer than 425 million people on the planet had even reached their 65th birthday.

The shape of things to come is suggested by mind-bending projections for countries at the vanguard of tomorrow’s depopulation: places with abidingly low birth rates for over half a century and favourable life expectancy trends. South Korea provides the most stunning vision of a depopulating society just a generation away. Current projections have suggested that South Korea will mark three deaths for every birth by 2050. In some UNPD projections, the median age in South Korea will approach 60. More than 40 per cent of the country’s population will be senior citizens; more than one in six South Koreans will be over the age of 80. South Korea will have just a fifth as many babies in 2050 as it did in 1961. It will have barely 1.2 working-age people for every senior citizen.

Should South Korea’s current fertility trends persist, the country’s population will continue to decline by over three per cent per year—crashing by 95 per cent over the course of a century. What is on track to happen in South Korea offers a foretaste of what lies in store for the rest of the world.

Wave of Senescence

Depopulation will upend familiar social and economic rhythms. Societies will have to adjust their expectations to comport with the new realities of fewer workers, savers, taxpayers, renters, home buyers, entrepreneurs, innovators, inventors, and, eventually, consumers and voters. The pervasive greying of the population and protracted population decline will hobble economic growth and cripple social welfare systems in rich countries, threatening their very prospects for continued prosperity. Without sweeping changes in incentive structures, life-cycle earning and consumption patterns, and government policies for taxation and social expenditures, dwindling workforces, reduced savings and investment, unsustainable social outlays, and budget deficits are all in the cards for today’s developed countries.

Until this century, only affluent societies in the West and in East Asia had gone grey. But in the foreseeable future, many poorer countries will have to contend with the needs of an aged society even though their workers are far less productive than those in wealthier countries.

Consider Bangladesh: a poor country today that will be an elderly society tomorrow, with over 13 per cent of its 2050 population projected to be seniors. The backbone of the Bangladeshi labour force in 2050 will be today’s youth. But standardised tests show that five in six members of this group fail to meet even the very lowest international skill standards deemed necessary for participation in a modern economy: the overwhelming majority of this rising cohort cannot “read and answer basic questions” or “add, subtract, and round whole numbers and decimals.” In 2020, Ireland was roughly as elderly as Bangladesh will be in 2050—but in Ireland nowadays, only one in six young people lacks such minimal skills.
The poor, elderly countries of the future may find themselves under great pressure to build welfare states before they can actually fund them. But income levels are likely to be decidedly lower in 2050 for many Asian, Latin American, Middle Eastern, and North African countries than they were in Western countries at the same stage of population greying—how can these countries achieve the adequate means to support and care for their elderly populations?

In rich and poor countries alike, a coming wave of senescence stands to impose completely unfamiliar burdens on many societies. Although people in their 60s and 70s may well lead economically active and financially self-reliant lives in the foreseeable future, the same is not true for those in their 80s or older. The super-old are the world’s fastest-growing cohort. By 2050, there will be more of them than children in some countries. The burden of caring for people with dementia will pose growing costs—human, social, economic—in an ageing and shrinking world.

That burden will become all the more onerous as families wither. Families are society’s most basic unit and are still humanity’s most indispensable institution. Both precipitous ageing and steep sub-replacement fertility are inextricably connected to the ongoing revolution in family structure. As familial units grow smaller and more atomised, fewer people get married, and high levels of voluntary childlessness take hold in country after country. As a result, families and their branches become ever less able to bear weight—even as the demands that might be placed on them steadily rise.

Just how depopulating societies will cope with this broad retreat of the family is by no means obvious. Perhaps others could step in to assume roles traditionally undertaken by blood relatives. But appeals to duty and sacrifice for those who are not kin may lack the strength of calls from within a family. Governments may try to fill the breach, but sad experience with a century and a half of social policy suggests that the state is a horrendously expensive substitute for the family—and not a very good one. Technological advances—robotics, artificial intelligence, human-like cyber-caregivers and cyber-“friends”—may eventually make some currently unfathomable contribution. But for now, that prospect belongs in the realm of science fiction, and even there, dystopia is far more likely than anything verging on utopia.

The Magic Formula

This new chapter for humanity may seem ominous, perhaps frightening. But even in a greying and depopulating world, steadily improving living standards and material and technological advances will still be possible.

Just two generations ago, governments, pundits, and global institutions were panicking about a population explosion, fearing mass starvation and immiseration as a result of childbearing in poor countries. In hindsight, that panic was bizarrely overblown. The so-called population explosion was in reality a testament to increases in life expectancy owing to better public health practices and access to health care. Despite tremendous population growth in the last century, the planet is richer and better fed than ever before—and natural resources are more plentiful and less expensive (after adjusting for inflation) than ever before.

The same formula that spread prosperity during the twentieth century can ensure further advances in the twenty-first and beyond—even in a world marked by depopulation. The essence of modern economic development 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. With that formula, India, for instance, has virtually eliminated extreme poverty over the past half-century. Improvements in health, education, and science and technology are fuel for the motor generating material advances. Irrespective of demographic ageing and shrinking, societies can still benefit from progress across the board in these areas. The world has never been as extensively schooled as it is today, and there is no reason to expect the rise in training to stop, despite ageing and shrinking populations, given the immense gains that accrue from education to both societies and the trainees themselves.

Remarkable improvements in health and education around the world speak to the application of scientific and social knowledge—the stock of which has been relentlessly advancing, thanks to human inquiry and innovation. That drive will not stop now. Even an elderly, depopulating world can grow increasingly affluent.
Yet as the old population pyramid is turned on its head and societies assume new structures under long-term population decline, people will need to develop new habits of mind, conventions, and cooperative objectives. Policymakers will have to learn new rules for development amid depopulation. The basic formula for material advance—reaping the rewards of augmented human resources and technological innovation through a favourable business climate—will be the same. But the terrain of risk and opportunity facing societies and economies will change with depopulation. And in response, governments will have to adjust their policies to reckon with the new realities.

The initial transition to depopulation will no doubt entail painful, wrenching changes. In depopulating societies, today’s “pay-as-you-go” social programmes for national pension and old-age health care will fail as the working population shrinks and the number of elderly claimants balloons. If today’s age-specific labour and spending patterns continue, greying and depopulating countries will lack the savings to invest for growth or even to replace old infrastructure and equipment. Current incentives, in short, are seriously misaligned for the advent of depopulation. But policy reforms and private-sector responses can hasten necessary adjustments.

To adapt successfully to a depopulating world, states, businesses, and individuals will have to place a premium on responsibility and savings. There will be less margin for error for investment projects, be they public or private, and no rising tide of demand from a growing pool of consumers or taxpayers to count on.
As people live longer and remain healthy into their advanced years, they will retire later. Voluntary economic activity at ever-older ages will make lifelong learning imperative. Artificial intelligence may be a double-edged sword in this regard: although AI may offer productivity improvements that depopulating societies could not otherwise manage, it could also hasten the displacement of those with inadequate or outdated skills. High unemployment could turn out to be a problem in shrinking, labour-scarce societies, too.

States and societies will have to ensure that labour markets are flexible—reducing barriers to entry, welcoming the job turnover and churn that boost dynamism, eliminating age discrimination, and more—given the urgency of increasing the productivity of a dwindling labour force. To foster economic growth, countries will need even greater scientific advances and technological innovation.

Prosperity in a depopulating world will also depend on open economies: free trade in goods, services, and finance to counter the constraints that declining populations otherwise engender. And as the hunger for scarce talent becomes more acute, the movement of people will take on new economic salience. In the shadow of depopulation, immigration will matter even more than it does today.
Not all aged societies, however, will be capable of assimilating young immigrants or turning them into loyal and productive citizens. And not all migrants will be capable of contributing effectively to receiving economies, especially given the stark lack of basic skills characterising too many of the world’s rapidly growing populations today.

Pragmatic migration strategies will be of benefit to depopulating societies in the generations ahead—bolstering their labour forces, tax bases, and consumer spending while also rewarding the immigrants’ countries of origin with lucrative remittances. With populations shrinking, governments will have to compete for migrants, with an even greater premium placed on attracting talent from abroad. Getting competitive migration policies right—and securing public support for them—will be a major task for future governments but one well worth the effort.

The Geopolitics of Numbers

Depopulation will not only transform how governments deal with their citizens; it will also transform how they deal with one another. Humanity’s shrinking ranks will inexorably alter the current global balance of power and strain the existing world order.

Some of the ways it will do so are relatively easy to foresee today. One of the demographic certainties about the generation ahead is that differentials in population growth will make for rapid shifts in the relative size of the world’s major regions. Tomorrow’s world will be much more African. Although about a seventh of the world’s population today lives in sub-Saharan Africa, the region accounts for nearly a third of all births; its share of the world’s workforce and population are thus set to grow immensely over the coming generation.

But this does not necessarily mean that an “African century” lies just ahead. In a world where per capita output varies by as much as a factor of 100 between countries, human capital—not just population totals—matters greatly to national power, and the outlook for human capital in sub-Saharan Africa remains disappointing. Standardised tests indicate that a stunning 94 per cent of youth in the region lack even basic skills. As huge as the region’s 2050 pool of workers promises to be, the number of workers with basic skills may not be much larger there than it will be in Russia alone in 2050.

India is now the world’s most populous country and on track to continue to grow for at least another few decades. Its demographics virtually assure that the country will be a leading power in 2050. But India’s rise is compromised by human resource vulnerabilities. India has a world-class cadre of scientists, technicians, and elite graduates. But ordinary Indians receive poor education. A shocking seven out of eight young people in India today lack even basic skills—a consequence of both low enrolment and the generally poor quality of the primary and secondary schools available to those lucky enough to get schooling. The skills profile for China’s youth is decades, maybe generations, ahead of India’s youth today. India is unlikely to surpass a depopulating China in per capita output or even in total GDP for a very long time.

A New Chapter

The era of depopulation is nigh. Dramatic ageing and the indefinite decline of the human population—eventually on a global scale—will mark the end of an extraordinary chapter of human history and the beginning of another, quite possibly no less extraordinary than the one before it. Depopulation will transform humanity profoundly, likely in numerous ways societies have not begun to consider and may not yet be in a position to understand.

Yet for all the momentous changes ahead, people can also expect important and perhaps reassuring continuities. Humanity has already found the formula for banishing material scarcity and engineering ever-greater prosperity. That formula can work regardless of whether populations rise or fall.

Humanity bestrides the planet, explores the cosmos, and continues to reshape itself because humans are the world’s most inventive, adaptable animal. But it will take more than a bit of inventiveness and adaptability to cope with the unintended future consequences of the family and fertility choices being made today.