Gabriel G. Tabarani*
For the first time since the Black Death swept across Eurasia seven centuries ago, humanity is heading toward a future in which the global population will begin to shrink. But unlike the 14th-century catastrophe, this demographic turning point is not driven by plague, famine, or war. It is the result of millions of private decisions, made in bedrooms and clinics and quiet conversations, as people across the planet choose to have far fewer children than their parents did.
This shift is happening faster and more broadly than most policymakers—or even most demographers—a generation ago thought possible. East Asia’s great economies, from China to South Korea to Japan, are already in population decline. Europe has been below replacement fertility for half a century. Latin America and parts of the Middle East, once associated with high birthrates, now see fertility levels at or below those of Italy or Germany. India, now the world’s most populous country, has slipped under replacement fertility in many of its states and major cities. The only major region still firmly above replacement is sub-Saharan Africa—and there, too, birthrates are falling steeply.
For a long time, the world assumed that more people was the default. Nations planned their economies around expanding workforces, growing consumer markets, and ever more students in schools. That assumption is now breaking down. In the coming decades, more and more countries will enter what demographers call “net mortality”: the moment when deaths outnumber births, year after year. By mid-century, well over a hundred countries—home to a majority of humanity—are projected to be in this zone.
The consequences will reach far beyond demography. Economies built on the expectation of perpetual expansion will encounter a new reality: smaller cohorts of workers supporting larger cohorts of retirees. Social security and pension systems, designed in an era of broad-based growth, will strain under the weight of aging populations. Health-care systems will be forced to deal with a sharp rise in costly chronic conditions, dementia chief among them. Politicians will face an uncomfortable question: who pays for all this, in societies with fewer taxpayers and more people needing care?
What makes this moment especially striking is that it is not being imposed on us by nature. It is driven by human agency. Around the world, surveys show a tight link between the number of children women say they want and the number they actually have. The most powerful predictor of national fertility, it turns out, is not income, religion, or access to contraception. It is preference. And preferences have shifted.
The classic story once told in development circles ran like this: as countries grow richer, healthier, and more educated, families choose to have fewer children. There is truth in that narrative—but it is no longer sufficient. Today, countries with fragile economies, weak schools, and limited public services have also dropped below replacement. Myanmar and Nepal, for example, have fertility levels more typical of aging European societies than of poor, rural ones.
What, then, is going on? Part of the answer lies in a quiet revolution in family life. Marriage comes later, if it comes at all. Cohabitation and temporary partnerships are more common. Single-person households are rising fast. Religion, which traditionally encouraged both marriage and childbearing, is weakening in many places. At the same time, the cost—financial, emotional, and practical—of raising children has risen sharply, especially in cities where housing, education, and childcare are expensive. Autonomy, self-realization, and flexibility have become prized. Children, for all their joys, are the ultimate long-term commitment.
There is also a powerful element of imitation. Large families have become rarer, and therefore less imaginable. When friends, colleagues, and neighbors have one child—or none at all—choosing to have three or four is no longer just a financial or logistical decision; it is a social anomaly. In that sense, low fertility becomes a self-reinforcing norm. Once a society has crossed into very low birthrates, it can be hard to find the way back.
The geopolitical implications are no less significant. States have always drawn strength from their people: workers, soldiers, taxpayers, innovators. In the emerging age of depopulation, many of the powers currently challenging the international order will find themselves fighting against demographic gravity. Russia has suffered more deaths than births for decades. China’s workforce is already shrinking, and its birth collapse means that future cohorts will be even smaller. Iran, despite its youthful image in Western media, has one of the most sharply fallen fertility rates in the world.
By contrast, the United States remains something of an outlier. Its fertility, although below replacement, is higher than that of most affluent societies, and immigration continues to replenish its labor force. If Washington sustains an open stance toward immigration and invests in education and innovation, demographics could underpin U.S. power even as rivals age and contract.
None of this means that a shrinking world is doomed to stagnation. The key insight from the last century of economic history is that prosperity depends less on how many people there are and more on what they are able to do. Advances in technology, improvements in education, and better health have allowed societies to generate wealth far beyond what earlier generations imagined possible. That logic still holds in a graying world. Higher productivity, longer working lives, smarter use of technology—including artificial intelligence—and better training can offset some of the drag from smaller cohorts.
But adaptation will require painful changes. Retirement ages will have to rise. “Pay-as-you-go” pension systems will need reform, or they will collapse under their own arithmetic. Labor markets must become more flexible, allowing people to retrain and re-enter work at later ages. Immigration, already politically fraught, will become a central pillar of economic strategy—and countries unable or unwilling to integrate newcomers will find themselves at a serious disadvantage.
Perhaps the most unsettling challenge lies not in economics, but in social fabric. Families are still the primary providers of care. As they grow smaller and more dispersed, and as childlessness rises, the question becomes: who looks after the very old? The state is an expensive and imperfect substitute. Robots and AI companions may someday help, but for now they live mostly in the imagination of tech futurists—and in their darker visions, those futures are more dystopian than comforting.
We are, in other words, stepping into a world we have never known: one where decline, not growth, is the baseline; where societies are older, thinner, more fragile; where the arithmetic of power and prosperity is being rewritten. Yet human beings are nothing if not adaptable. The same capacity for choice that has brought us into the age of depopulation can, if we are honest about the trade-offs ahead, help us navigate it.
What we cannot afford is to pretend that nothing fundamental has changed. The world is still full of young people today, especially outside the rich countries. But the pipeline behind them is narrowing. When the world stops growing, the societies that thrive will be those that recognize the shift early, confront its hard truths, and design institutions for an era in which more is no longer guaranteed.
This article was originally published in Arabic on the Asswak Al-Arab website
