The debate about collapsing fertility usually begins with the assumption that something has gone wrong and that, if governments can only identify the malfunction, they can repair it. Houses are too expensive, childcare costs too much, wages are inadequate, employment is insecure, governments tax families excessively or welfare states have weakened the economic function of children. Each explanation contains some truth, and the Mises Institute's recent argument about interventionism identifies several genuine burdens placed upon family formation. But there is a more disturbing possibility. What if the birth dearth is not principally a malfunction of modern society at all? What if it is one of modernity's characteristic outcomes?
The conventional demographic transition theory already takes us a considerable distance towards this conclusion. Traditional societies generally combined high mortality with high fertility. Children died at rates almost unimaginable to inhabitants of wealthy countries today, families needed labour, parents depended upon descendants for support in old age, contraception was limited and marriage and reproduction were tightly bound together by economic necessity, religious belief and social expectation. Modernisation progressively dismantled that world.
Public health improved. Infant mortality collapsed. Agricultural societies became urban and industrial. Education expanded. Children changed from economically productive members of households into dependants requiring perhaps two decades or more of parental investment. Reliable contraception gave couples unprecedented control over reproduction, while pensions and welfare systems reduced dependence upon descendants in old age. Having six children ceased being economically necessary and became increasingly expensive.
Fertility consequently declined, just as demographic-transition theory predicted. But the process did not conveniently stop at the replacement level of roughly 2.1 children per woman. Across much of the developed world it simply kept going. The OECD average fertility rate had fallen to only 1.5 by 2022, while births were occurring increasingly late in women's lives. The mean age at childbirth across the OECD rose from 28.5 in 2000 to around 30.9 by the early 2020s.
The United Nations now describes below-replacement fertility as characteristic of a large part of the developed world. Every European country is below the long-term replacement level, while ultra-low fertility has appeared in societies as different as China, South Korea, Italy and Spain. This geographical spread is important because it immediately makes monocausal explanations difficult to sustain. These countries do not possess identical housing markets, welfare systems, tax structures or governments. Perhaps what we are witnessing is the demographic transition on steroids: the original transition reinforced by the cultural transformations that followed it.
Women's liberation is central to this development, and there is little point avoiding the subject because it is politically uncomfortable. This does not require condemning women's liberation or proposing that women be forced back into the social arrangements of 1900. It requires recognising that profound social changes have profound demographic consequences. For most of history, women's range of socially acceptable life trajectories was narrow. Marriage and motherhood were overwhelmingly expected, while economic independence was difficult and professional careers were available to relatively few. Modernisation transformed those circumstances. Women acquired higher education in enormous numbers, entered virtually every profession, achieved much greater economic independence and gained the ability to construct meaningful adult lives that did not necessarily depend upon marriage or motherhood.
These were enormous expansions of individual freedom, but they also transformed the economics of reproduction. The opportunity cost of having a child is very different for a woman whose alternatives are limited to domestic and poorly paid employment from that faced by a woman who has spent years acquiring a university degree and establishing a professional career. Pregnancy, childbirth and childcare consume time during precisely the period when careers are frequently being established. OECD analysis explicitly identifies increasing opportunity costs associated with motherhood as incomes rise and women gain greater equality in education and employment as part of the global fertility decline.
This does not mean educated women necessarily reject children. Indeed, the relationship between education and fertility has become more complicated, and in some Nordic countries highly educated women are now more likely than less educated women to have children. Policies that make work and parenthood compatible can therefore make a genuine difference. But the larger transformation remains: motherhood is no longer the overwhelmingly predetermined female destiny it once was. It has become a choice competing against other choices, and once that occurs, the demographic mathematics changes profoundly.
A woman marrying at twenty and beginning childbearing shortly afterwards could relatively easily have four children before thirty. A woman who spends her twenties obtaining qualifications, establishing a career, travelling, finding a suitable partner and accumulating enough money for a house may not attempt her first pregnancy until her early thirties. Having three or four children then becomes biologically and practically much more difficult even if that was once her preference. Delayed fertility is therefore not simply the result of women deciding they dislike children. It can arise from millions of individually reasonable decisions that collectively produce demographic decline.
The same applies to men. Extended education, insecure early employment, expensive housing and changing relationship patterns can postpone the point at which men regard themselves as capable of supporting families. Marriage itself occurs later, if it occurs at all. Modern societies have effectively stretched adolescence and early adulthood while leaving human reproductive biology largely where evolution placed it.
Then came what demographers describe as the second demographic transition. The first transition reduced fertility through modernisation; the second involved deeper changes in values, relationships and individual autonomy. Marriage weakened as a universal institution. Divorce became easier and more common. Cohabitation became normal. Contraception and abortion further separated sexual relationships from reproduction. Secularisation weakened religious injunctions concerning marriage and children, while voluntary childlessness became increasingly socially acceptable. Most importantly, perhaps, the meaning of the good life changed.
Traditional cultures tended to locate the individual inside institutions larger than himself: family, church, community and nation. Modern liberal culture increasingly locates meaning within individual choice. The successful life becomes the self-authored life. Education, career, travel, experiences, relationships, consumption and personal development all become legitimate competing projects. Children are unusual competitors in this marketplace because they require precisely the opposite psychology.
A child radically limits autonomy. Children cost money, interrupt sleep, restrict travel, complicate careers and require years of putting somebody else's interests ahead of one's own. They cannot be fitted neatly into a culture organised around maximum personal flexibility. Previous societies solved this problem largely by not treating parenthood as an optional consumer preference. Having children was simply what adults normally did. Religion commanded it, families expected it, communities reinforced it and economics often rewarded it. Modernity has dismantled much of that machinery.
This creates a paradox that neither libertarians nor progressives find particularly comfortable: the birth dearth may partly be the consequence of freedom itself. Give human beings reliable contraception, economic security independent of descendants, sexual freedom, geographical mobility, long periods of education, numerous leisure possibilities and the ability to construct socially respectable lives without children, and many will choose fewer children. Some will choose none. No dictator needs to impose this result, no conspiracy is required and nobody even needs to desire the aggregate outcome. Millions of individually rational choices can produce a collectively disastrous result.
This is why government attempts to reverse ultra-low fertility have proved so frustrating. Policymakers instinctively approach the problem as economists: if children have become too expensive, subsidise them. Provide childcare, parental leave, cash payments, tax concessions and housing assistance. These measures can reduce genuine burdens and are often worth implementing regardless of their demographic effect. They can also increase fertility at the margin. The OECD finds that making employment and family life more compatible matters, while economic insecurity and housing affordability matter as well. But there is little reason to believe that another baby bonus will recreate the demographic world that modernity destroyed.
South Korea provides the extreme example. Its fertility collapse has become so severe that the OECD describes the country as facing an unprecedented demographic challenge. Yet Korea has substantially expanded family policies, childcare and financial support. The OECD concludes that family policies are part of the solution but not a cure-all, and that fertility gains from many interventions have remained limited.
Korea also demonstrates why women's liberation cannot simply be blamed in some crude sense. Korean women face an unusually severe conflict between professional life and traditional expectations surrounding motherhood. The problem is not simply that women have careers; it is that the institutions surrounding them have often failed to adapt sufficiently to the fact that they do. Making that conflict less severe is desirable. A society should not unnecessarily force women to choose between having children and using their education and talents.
But suppose we solved the problem perfectly. Suppose houses became cheaper, childcare excellent, workplaces flexible and parenthood substantially easier. Would fertility return permanently to 2.1? Nobody knows, and the experience of wealthy countries gives little reason for certainty. Fertility has remained below replacement across societies with widely varying institutional arrangements. Even countries regarded as exceptionally family-friendly have struggled to maintain earlier fertility levels. Economic reforms may raise fertility without restoring replacement.
That suggests the deeper problem is cultural as well as economic. Modern societies have become extremely good at teaching people how to achieve individual aspirations and remarkably poor at explaining why they should produce the next generation. The old answer was largely taken for granted: you had children because children were part of life. The modern individual reasonably asks a different question: why should I? That question is surprisingly difficult for a secular consumer society to answer.
Children will not necessarily make you wealthier. They may damage your career. They will certainly reduce your disposable income. They restrict freedom and create enormous responsibility. If personal autonomy and consumption are the principal measures of a successful life, having several children can look positively irrational. The case for parenthood depends upon values that resist economic calculation: love, continuity, inheritance, sacrifice, belonging and an obligation to generations not yet born. A civilisation that loses confidence in those concepts will have difficulty reproducing itself regardless of how generous its childcare subsidies become.
This is where the birth dearth becomes more than a demographic problem; it becomes a philosophical problem. Modernity promised liberation from inherited obligations and, increasingly, it delivered that liberation. People became freer to choose where they lived, what they believed, whom they married, whether they married and whether they reproduced. But civilisation itself depends upon at least one behaviour that cannot disappear merely because individuals find alternatives more attractive: somebody must have the children.
There is no technological substitute yet for producing the next generation of human beings. Artificial intelligence may replace some workers, robots may care for elderly people and automation may allow smaller working populations to produce much more. These developments could make population ageing substantially easier to manage, but they do not eliminate the underlying arithmetic. A fertility rate substantially below replacement means each generation eventually becomes smaller than the generation before it. Population momentum and immigration can conceal the process for decades, but they cannot abolish it.
Immigration is particularly misleading as a supposed solution. It can certainly slow population decline in individual countries and improve the ratio of workers to retirees for a period. Australia has relied heavily upon precisely this mechanism. But immigration cannot solve a global fertility problem. Migrants must come from somewhere, and as fertility falls across more of the developing world, the pool of youthful high-fertility populations will itself diminish. Moreover, descendants of migrants generally become exposed to the same economic and cultural forces operating in their destination societies. Immigration can redistribute population geographically; it cannot manufacture an indefinitely expanding supply of young human beings.
The United Nations projections illustrate the scale of the long-term adjustment already underway. China, once synonymous with fears of overpopulation, is projected to experience extraordinary population decline over the remainder of the century if current demographic trajectories broadly persist. This reversal should transform how we think about population.
For much of the twentieth century intellectuals worried about a population explosion. Paul Ehrlich and others predicted mass starvation as humanity multiplied beyond the planet's capacity. Governments and international organisations consequently spent decades thinking about how to reduce fertility. Modernisation proved astonishingly effective at doing precisely that; perhaps too effective. We are now discovering that moving fertility downward is much easier than moving it upward.
That asymmetry makes sense. The forces reducing fertility largely expand choice. Contraception permits people to avoid unwanted births. Education expands alternatives. Wealth makes children less economically necessary. Urbanisation raises their costs. Secularisation weakens reproductive obligations. Reversing those forces would require measures that almost nobody in a liberal society seriously wants. We are not going to remove women's educational opportunities, prohibit women from professional careers, abolish contraception, force people to marry at twenty or compel couples to produce three children. Nor should we.
This is why the most uncomfortable conclusion may also be the most realistic: perhaps we must accept a considerable degree of demographic decline. That does not mean celebrating it. Governments should remove unnecessary barriers to family formation. Housing policy should not make a family home needlessly unaffordable. Tax systems should not punish couples who choose to raise several children. Workplaces should make it possible for men and women to combine parenthood with productive careers. A society worried about fertility should certainly stop making parenthood more difficult than it inherently is.
But there is a difference between making children possible for people who want them and persuading an entire civilisation to want enough children to reproduce itself. The first is a plausible policy objective; the second may not be.
This is where the free-market analysis of the birth dearth reaches its limit. Government intervention can increase housing costs, distort incentives and weaken family independence. Remove those distortions and prospective parents may indeed have more children. But Switzerland, Sweden, Japan, Italy, Spain, South Korea and Australia are not all suffering from the same government intervention. They are all modern, and that may be the more important common variable.
Modernisation brought extraordinary benefits: longer lives, lower infant mortality, education, wealth, women's freedom, reproductive choice and individual autonomy. Those achievements should not casually be discarded because they carry demographic consequences. Yet intellectual honesty requires recognising that benefits can have costs. Perhaps the great demographic irony of modern civilisation is that societies became so successful at liberating individuals from the old necessities of reproduction that reproduction itself became optional. Once it became optional, insufficient numbers chose enough of it.
There may be no policy lever capable of completely reversing that result without sacrificing freedoms we have no intention of surrendering. If so, the sensible response is not endless panic about restoring the population pyramid of 1960, but adaptation to a smaller and older civilisation. Automation will have to compensate for fewer workers. Retirement systems will have to change. Cities may eventually have to adjust to shrinking rather than perpetual growth. Governments will need to abandon economic models dependent upon indefinitely increasing populations. Communities will have to learn how to maintain institutions with fewer young people. Above all, we may need to abandon the assumption that every demographic trend can be engineered into submission.
Human beings wanted freedom from biological, economic and social constraints, and modernity gave them more of it than any civilisation in history. They used some of that freedom to have fewer children. The birth dearth may therefore be neither a mysterious pathology nor something caused by one bad government policy. It may be the demographic price attached to the civilisation we deliberately constructed.
We can reduce that price. We can make family life easier, honour parenthood more strongly and stop economically penalising people who produce the next generation. Perhaps cultural changes will eventually produce some fertility recovery as societies adapt to the consequences of extreme individualism. But we should also entertain the possibility that the old demographic world is not coming back.
The demographic transition may have contained its own momentum all along. Modernisation reduced the need for children; affluence increased their relative cost; contraception made them optional; women's liberation enormously expanded alternatives to motherhood; and individualism weakened the cultural expectation that adults should reproduce themselves. Taken separately, these were understandable and often desirable developments. Taken together, they produced something few of their advocates intended: societies increasingly unwilling or unable to replace themselves.
That is the demographic transition on steroids. If retaining the freedoms of modernity means that no liberal-democratic government can fully reverse it, then perhaps our task is no longer to pretend that some sufficiently ingenious subsidy will restore the past. It is to work out how civilisation goes down in numbers without going down with them.