Japan: Fertility Rate Trends by Income & Education among People Born 1943–1975
A 2022 study (Salaries, degrees, and babies: Trends in fertility by income and education among Japanese men and women born 1943–1975—Analysis of national surveys by Cyrus Ghaznavi, Haruka Sakamoto, Lisa Yamasaki, Shuhei Nomura, Daisuke Yoneoka, Kenji Shibuya, and Peter Ueda) investigates trends in the number of children and total fertility among Japanese men and women born between 1943 and 1975. Using data from four rounds of the National Fertility Survey, the authors examine how these fertility outcomes differ by education and income and how gaps have changed across birth cohorts.
Background and Motivation
Japan experienced a dramatic decline in fertility rates in the second half of the 20th century, with total fertility falling below 1.0 births per woman in 2018—the lowest in the world. While this trend is well-known, less is understood about whether the decline is driven by a growing proportion of the population remaining childless, a decrease in the number of children among those who have kids, or both.
Moreover, there are conflicting hypotheses about how fertility outcomes vary by socioeconomic status. Lower incomes may deter childbearing due to the costs of raising children, while highly educated women may face challenges balancing career and family. The authors aim to shed light on these questions.
Data and Methods
The study uses the National Fertility Survey, which covered married and unmarried individuals from 1992, 2005, 2010, and 2015. The analysis focuses on men and women aged 40-49, capturing fertility outcomes near the end of reproductive years for 5-year birth cohorts from 1943-1947 to 1971-1975.
Two key outcomes are examined:
Distribution of the number of children (0, 1, 2, or 3+)
Total fertility (mean number of children)
These outcomes are assessed by education (university degree vs. no degree) for both genders and by income (low, middle, high) for men. Logistic regression estimates associations of detailed sociodemographic factors with childlessness and having 3+ children in the 1971-75 cohort.
Key Findings
From the 1943-47 to 1971-75 birth cohorts, childlessness rose from 14% to 40% for men and 12% to 28% for women. Total fertility fell from 1.92 to 1.17 for men and 1.96 to 1.42 for women.
Except for the oldest cohort, men with a university degree were likelier to have children than those without a degree. From the 1956-60 to 1966-70 cohorts, university-educated women were less likely to have children, but this gap closed for the 1971-75 cohort.
Men with higher incomes consistently had more children. While fertility declined across all income groups, the fall was steepest for low-income men, exacerbating disparities.
In the 1971-75 cohort, men who were unemployed or in non-regular jobs and women in regular employment were more likely to be childless. Women in large cities had the lowest fertility.
Contributions and Implications
This study makes several notable contributions:
It is one of few to examine fertility trends among men, highlighting growing income disparities.
For women, the closing educational gap in the most recent cohort suggests a potential shift in how higher education shapes fertility.
Assessing both childlessness and the number of children provides a more complete picture of how fertility patterns change.
The findings underscore the role of economic security in enabling family formation, particularly for men. The association of non-regular employment with childlessness is concerning given the decline in stable jobs in recent decades.
For women, the disappearance of the educational fertility gap in the youngest cohort is intriguing and warrants further study. It may reflect the increasing importance of women's economic prospects in Japan's marriage market.
While data limitations preclude strong causal claims, this study offers valuable descriptive evidence on the socioeconomic dimensions of Japan's fertility decline. Continued monitoring of these trends and further research on the barriers to childbearing will be critical as the country grapples with a historically low birth rate. Policies that mitigate the economic obstacles to family formation while supporting work-family balance may have an important role to play.