Japan’s Regional Birthrate Divide: A Demographic Investigation

In 2025, Japan's total fertility rate dropped to a record low of 1.14 children per woman, with Tokyo leading the way at 0.96. According to Japan's Ministry of Health, Labor, and Welfare, the eastern regions of the country, including Miyagi, Hokkaidō, and Akita, had lower fertility rates than areas in the west, such as Okinawa, Miyazaki, Nagasaki, and Kumamoto. Researchers have tried to pinpoint the reasons for this disparity, but no definitive cause has been identified.

The analysis of census data and demographic statistics from 1990 to 2020 reveals that the decline in births in Hokkaidō/Tōhoku was primarily due to a combination of factors, including a smaller proportion of women of childbearing age, lower marriage rates, and a lower fertility rate among married women. In contrast, Kyūshū experienced the decline mainly because of a shrinking population of women of childbearing age.

The shift towards remaining single or marrying later in life, often linked to higher education attainment, is a key driver in the declining birth rates. A comparison of the marriage rates of 25-year-old women by prefecture shows that a higher proportion of university-educated women is correlated with a lower marriage rate. In Hokkaidō/Tōhoku, the rapid rise in women's university enrollment in recent years has contributed to the decline in marriage rates among the younger generation.

Although no definitive economic, social, or demographic factors have been identified as the sole cause of the fertility rate divide between Hokkaidō/Tōhoku and Kyūshū, the analysis suggests that the changing social dynamics, particularly the increasing number of women pursuing higher education and delaying marriage, have played a significant role in shaping the birthrate trends in Japan.