Why reversing China’s demographic decline will prove far harder than Beijing may reckon

Having finally acknowledged the country’s grim demographic reality, Chinese authorities introduced new pro-natalist policies last year, expecting the number of births to rebound. But a decline in China’s fertility rate was inevitable, like a boulder rolling down a hill. Even if it can be pushed back uphill, it will not happen quickly.

After all, the downward trend in marriages will be difficult to reverse, since the number of women aged 20-34, who account for 85% of Chinese births, is expected to drop from 105 million in 2025 to 58 million by 2050.

Compounding this, China’s marriage market suffers from a pronounced mismatch. Decades of sex-selective abortion have created a severe shortage of women of childbearing age and women’s higher educational attainment has created a ‘leftover women’ phenomenon, with female students outnumbering males.

Whereas the male-to-female ratio among six-year-olds in 2010 was 119:100, by 2022, when this cohort entered college, the ratio in undergraduate admissions was only 59:100. As a result, more men are unable to find wives and more women are likely to remain unmarried, given their preference for more highly educated husbands.

China’s current policies are a scaled-down version of Japan’s ineffective response to demographic decline. In Japan, fertility fell from 1.45 (far below the replacement rate of 2.1) in 2015 to 1.15 in 2024. With China facing even deeper structural demographic constraints, it is not surprising that its fertility rate has already fallen below Japan’s.

It is an ecological law that density inhibits the growth of bacteria, plants and animal populations, and humans are no exception. Across wards and cities in Tokyo, population density is negatively correlated with fertility rates; the same pattern can be found in London, New York, and Shanghai.

Built-up urban areas in the US typically have 800-2,000 people per sq km, compared to about 6,000 per sq-km in Tokyo. In China, the average is 8,900 per sq km, with many districts in first- and second-tier cities, where young people flock, often reaching 20,000-30,000 per sq km.

High population density drives up housing costs, while higher price-to-income ratios negatively affect fertility. In recent years, declining fertility in Canada, the US and Europe has been partly driven by soaring housing prices.

Since China’s price-to-income ratio far exceeds Japan’s, and since its housing bubble is much larger, boosting fertility would require transforming (demolishing and rebuilding) its cities to lower their population density and housing costs. Doing that could trigger a financial crisis or even an economic collapse.

Japan’s experience also shows that the average age for men and women at first marriage is negatively correlated with fertility, as is the proportion of unmarried women aged 25-29. In China, the average age at first marriage rose from 26 for men and 24 for women in 2010 to 29 and 28, respectively, in 2020. Worse, the share of unmarried women aged 25-29 surged from 9% in 2000 to 33% in 2020 and to 43% in 2023.

The Chinese government has introduced a “new quality productive forces" policy to offset the drag of ageing on the economy. But such pro-growth measures will inevitably prolong education, which will delay childbearing, increase the proportion of unmarried individuals and lower fertility further.

Again, Japan shows that there are no easy solutions. It funded childbirth subsidies by raising its consumption tax. But the burden ultimately fell on households, reducing disposable income as a share of GDP, which has fallen from 62% in 1994 to 55% in 2024, a loss that subsidies can scarcely offset.

Similarly, Taiwan’s fertility rate fell from 1.68 in 2000 to 0.72 in 2025, partly reflecting the decline in household disposable income from 67% of GDP to 55%. In mainland China, household disposable income already accounts for only 43% of GDP, making child-rearing even more difficult.

China’s best option to increase fertility would be to raise its household income share, which would also boost consumption and absorb excess capacity. But Beijing is unlikely to pursue such a paradigm shift because it could weaken its own finances and power, potentially reshaping China’s political landscape.

Moreover, even if China could afford to increase fertility by providing generous social benefits, the effects would not last, because such interventions risk weakening family structures and reducing male labour-force participation. After Nordic countries adopted similar policies, the proportion of children born out of wedlock surged to 50-70%, with taxpayers supporting the elderly.

This collectivist model, reminiscent of China’s Great Leap Forward (1959-62) that led to millions of famine deaths, is unsustainable. The strength of a chain is determined by its weakest link, and in China’s case, several links need strengthening. Fertility can rise only if China addresses them all. One hopes that it can set an example that does not violate human rights. ©2025/Project Syndicate

The author is a senior scientist at the University of Wisconsin, Madison, and spearheaded a movement against China’s one-child policy.