Japan vs South Korea: better living standards alone do not lift fertility
- Main cause
- The AI's hypothesis: costs that averages hide, such as housing and child-rearing, may weigh on having children (untested here).E-12E-08
The AI's own summary of its diagnosis and policy. Figures are checked against the evidence.
Total fertility rate (South Korea) 1990 → 2001 −17%
In 1990 the total fertility rate was at almost the same level in both countries: about 1.6 in South Korea and about 1.5 in Japan. Korea was still higher in 2000, but by 2001 it had fallen below Japan.
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Between 2012 and 2024 the total fertility rate fell about 42% in South Korea and about 18% in Japan. Korea's 2024 figure was about 65% of Japan's.
Real household consumption per person (2015 US dollars) rose about 23% in South Korea between 2012 and 2024, while Japan's grew only slightly. Korea's level was about 39% of Japan's in 1990 and about 89% in 2024.
Female labour force participation was lower in South Korea than in Japan in 1990. In 2024 it was about 57% in Korea and about 56% in Japan, putting Korea ahead.
GDP per person (nominal, US dollars) in South Korea was about 26% of Japan's in 1990. In both 2024 and 2025 Korea was ahead; in 2024 it was about 36 thousand dollars in Korea and about 34 thousand in Japan.
In South Korea, real household consumption per person rose about 23% between 2012 and 2024 while the fertility rate fell about 42%. The natural reading, in our view, is that a better average standard of living does not by itself raise fertility. One hypothesis is that costs hidden by averages, such as housing or child-rearing costs, weigh on decisions to have children, but the materials contain no spending breakdown that could test this.
In 2024 female labour force participation was about 57% in South Korea and about 56% in Japan, so it is higher in Korea, where fertility is lower. These two countries' figures support neither "women working means fewer children" nor "more working women means more children." In our view the question is less whether women work than whether they can raise children while working. Options include wider parental leave and childcare, which helps families but adds costs for employers and taxpayers, and larger cash benefits, which give families freedom in how to spend, though Korea's rising household consumption alongside falling fertility suggests money alone may not be enough.
What sets Japan apart is that its fertility rate has fallen more gently than Korea's while its population is far older: in 2024 people aged 65 and over were about 30% of the population in Japan and about 19% in South Korea. If support for child-rearing is funded mainly by the working-age population, Japan is more likely to face competition with spending on older people, which could make the funding debate harder than in Korea.
Much is left unsaid by the data. GDP per person is in nominal US dollars and swings with exchange rates, so reading it as "Korea has overtaken Japan" calls for caution. The materials also include marriage counts for Japan but no marriage data for South Korea, so we cannot tell here whether Korea's fertility decline comes from fewer marriages or fewer children per couple. Korea's fertility rate rose from about 0.72 in 2023 to about 0.75 in 2024, but one year is too soon to call a turnaround.
One view holds that setting average living standards against the fertility rate is the wrong comparison altogether. The total fertility rate moves with how many people give birth in a given year, and it can drop sharply for a while simply because people have children later. As Korea's rise in 2024 hints, part of the decline may be made up later. If so, it is too early to conclude from consumption and labour figures that better living standards do not bring more children; that judgment needs completed family size by age group.
How it is made: claude-opus-5-5 · prompt 8dc838ce54de