What are the main reasons for the decline in China's population?

China’s population is shrinking for reasons that are structural rather than temporary, and the story is as much about economics and institutions as it is about births and deaths. The headline numbers attract attention, but the underlying forces are the slow turning gears of fertility choices, marriage patterns, the cost of raising children, and the rules that shape life in cities. When these elements move together in the same direction, population decline begins to look less like a brief detour and more like a long road.

At the center of the picture is fertility. For years, the number of children that the average woman is expected to have has remained well below the level needed to replace the population. Policy has shifted from one child to two and then to three, yet births have not rebounded in a decisive way. The reason is not that families misunderstood the rules. It is that the constraints they face are real and immediate. When the cost of a larger family feels high and the payoffs from additional children feel uncertain, declarations of support are not enough to change behavior. In this sense, fertility is a mirror of household economics. Couples act on what they can afford, what they can plan for, and what they believe will be possible across the next two decades, not only on what a policy document permits.

Marriage patterns reinforce the trend. In China, most births still occur within marriage, so a contraction in marriage registrations today reduces the pool of births one to three years ahead. After a brief normalization following the pandemic, marriages have slipped again, reaching lows not seen since records began. Fewer young adults are choosing to wed, and those who do are often older and more cautious. The drivers are familiar to any young couple trying to sketch a budget. Housing is expensive in the cities where jobs exist. Work feels less predictable than it did during years of fast growth. The property market, which once gave families a sense of steady wealth accumulation, has corrected and become a source of caution rather than confidence. When income paths look flatter and assets feel less secure, people delay commitments, and family formation becomes a later life project or, for some, not a project at all.

Costs are the most visible constraint because they are the ones families have to meet each month. Urban households face a three-part bill that dominates the conversation at the dinner table: housing, education, and childcare. Mortgage payments or high rents absorb a large share of income. Education costs begin with preschool and intensify through tutoring cultures that parents feel they cannot opt out of without placing their children at a disadvantage. Childcare is often scarce or costly, which turns time into a second currency that must be spent by a parent or grandparent. Families then adapt. The ideal of two children is replaced by a calculation that favors one child, and for a growing number of couples, the calculation points to postponement or child-free living. Small subsidies can soften a single edge of this problem but struggle to overcome the combined weight of these three categories.

History still casts a shadow over today’s choices. The one-child era shaped norms, expectations, and family structures for a generation. It influenced the sex ratio and left more males than females in the prime ages for marriage, a mismatch that complicates the search for a partner in some regions. These are not overnight effects. They work through the marriage market year after year and alter the trajectories of towns and villages, especially where opportunities are thinner and out-migration stronger. While the imbalance is gradually easing, its legacy is not easily erased, and it adds another layer of difficulty to the task of raising the marriage and birth counts.

Urbanization and internal migration have powered China’s growth story, but they have also introduced frictions that affect family size. The household registration system determines the benefits families can access in a given city, from schooling to healthcare. When a migrant family does not receive full urban entitlements, the implicit price of an additional child in that city rises. Some local governments have experimented with easing these barriers and granting fuller rights, and where that occurs families show small positive responses. Yet the scale of strictures across large metros still acts as a tax on fertility. The result is a pattern in which workers move to the places where jobs are, but the decision to have a second child remains tethered to hometowns where support networks and entitlements are stronger. That mismatch between where people live and where they can afford to raise children pinches the birth rate.

Labor market conditions layer on top of these structural issues. Youth unemployment concerns, an economy moving from property-heavy growth to a more subdued and rebalanced profile, and an evolving tech and services landscape all filter into household decision making. The long expansion had accustomed many to steady wage growth and rising home values. A slower, more uncertain environment induces precaution. Couples postpone costly life choices until the outlook clarifies. Postponement in turn reduces fertility because the biological window narrows and because late starts make larger families statistically less likely.

Mortality dynamics have also shifted the arithmetic. The population is older than it was a generation ago, and a larger share of the population is now in age groups where mortality rates are higher. Health shocks in recent years added to the death count, and even as those shocks fade, the age structure alone keeps the level of deaths elevated. If births hover near nine to ten million and deaths run higher, natural decrease continues. That is not a judgment about the health system or an event driven anomaly. It is the predictable outcome of an age pyramid that has thinned at the base and widened toward the top.

Cultural expectations and workplace realities further influence the calculus. Long hours, uneven enforcement of protections for mothers, and career penalties associated with parental leave make the opportunity cost of childbearing high, particularly for educated women in competitive urban sectors. In surveys, many women report that the direct expense of a child is only part of the story. The indirect cost, measured in slower promotions, stalled projects, or reduced job security, can be decisive. Without strong parental leave rights, dependable childcare, and genuine penalties for discrimination, financial incentives tend to be transitory. Families treat them as short-term offsets rather than as guarantees that the system will support them across the full arc of raising a child.

Policy has begun to adjust. Local pilots for childcare and education support have been followed by national signals that the state will shoulder more of the early years’ burden. The logic is sound. Where countries have succeeded in lifting fertility from very low levels, they have done so with packages that make it possible to combine work and family rather than with one-off cash transfers. Affordable and abundant daycare, predictable parental leave with job protection, and a serious effort to contain education cost inflation are the core pieces. For China there is a fourth piece as well, which is the portability of benefits for people who live and work in cities different from their place of registration. If fiscal resources are limited, prioritizing childcare infrastructure and urban entitlement portability is likely to deliver more lasting effects than a broad set of small grants.

The economic consequences of a shrinking population are not simple negatives. A smaller youth cohort changes the shape of consumption and the demands placed on housing markets. An older society will save and invest differently, and labor scarcity can raise the value of productivity-enhancing technologies. If credit allocation is efficient and competition remains strong, firms can respond with automation and process upgrades that offset some of the pressure from a tighter labor pool. Yet even under optimistic productivity scenarios, the demographic baseline still points to fewer births and a smaller workforce. Planning for that reality means investing in human capital, reinforcing social safety nets for an aging population, and aligning urban policy with the places where people actually live.

All of this returns us to the original question. The main reasons for the decline in China’s population are cumulative and mutually reinforcing. Fertility remains low despite permissive rules because families face high direct and indirect costs. Marriage registrations have fallen, which narrows the pipeline of future births. Housing, education, and childcare consume a large share of household resources and raise the shadow price of each additional child. Legacy imbalances in the sex ratio and the norms shaped by the one-child era still work through today’s choices. Urban rules make it harder for migrants to form and raise larger families in the cities where their jobs are located. A cooler labor market and slower wealth accumulation feed caution and delay. An aging population and recent health shocks keep deaths high relative to births. No single factor creates decline on its own, but together they anchor a trajectory that is difficult to reverse.

Reversal is not impossible, but it requires seriousness. Families respond to credible reductions in the time and money burdens of raising children, to confidence in jobs and housing, and to rules that treat them as citizens where they live. If those conditions take hold, fertility can lift from the floor, marriage can recover some ground, and population decline can slow. Until then, the most accurate way to describe China’s demographic shift is to see it as the product of policy history, cost structure, and institutional frictions working through family behavior. The numbers are the surface. The forces underneath are the real story.