A Data Analysis of the 744 'At-Risk' Municipalities — The Structure That Tokyo Siphons
A 2024 analysis by Japan's Population Strategy Council classified 744 municipalities (43.3% of all 1,729) as "at risk of disappearance." Meanwhile, 25 so-called "black-hole" municipalities attract young people yet suppress birth rates. This article reads the data-driven structure of Tokyo's concentration effect on national depopulation.
TL;DR
- The 2024 Population Strategy Council report classified 744 municipalities (43.3%) as at-risk, meaning their young female population will halve by 2050
- At-risk municipalities concentrate in Tohoku and Hokkaido; Kyushu and Okinawa have the most self-sustaining municipalities
- 21 of the 25 "black-hole" municipalities cluster in the Kanto region, absorbing young people while maintaining low birth rates
What is Happening
744 municipalities have been classified as at-risk; Tohoku and Hokkaido are the most affected, while Kyushu and Okinawa have the most self-sustaining municipalities.
On April 24, 2024, the private advisory body Population Strategy Council (chaired by Akio Mimura) classified 744 of Japan's 1,729 municipalities (43.3%) as "at-risk of disappearance." The definition: municipalities in which the population of women aged 20–39 will halve between 2020 and 2050 (cf. Population Strategy Council).
A key point of comparison is with the previous report. The 2014 "Masuda Report" (Japan Policy Council) classified 896 municipalities as at-risk; by 2024 that number had fallen to 744, with 239 municipalities escaping the designation. This shift is interpretable either as evidence that countermeasures worked, or as a sign that young female out-migration accelerated and completed earlier than projected.
Regionally, Tohoku and Hokkaido stand out as the most severely affected. 165 municipalities in the six Tohoku prefectures are classified as at-risk; combined with Hokkaido, approximately 282 municipalities are affected. In the most extreme cases, projected young female population declines reach 87.5%.
By contrast, Kyushu and Okinawa have the most "self-sustaining" municipalities — those in which young women will remain at close to 50% of current levels through 2100. 34 of 65 self-sustaining municipalities (52%) are located in Kyushu and Okinawa.
Background and Context
Young women migrate to cities for education and employment and do not return, doubly reducing birth numbers in rural areas.
Why Young Women Leave and Don't Return
Across differences in industry and geography, the structural common denominator among at-risk municipalities is: "young women leave for school or work and never return."
Young women who move to cities for high school or university spend the key life milestones — employment, marriage, childbirth — in urban areas. In regions with few jobs (especially for women), weak healthcare, education, and child-care infrastructure, the incentive to return is limited. Births that could have contributed to rural statistics instead count in the destination city. The origin region loses population twice over.
The Specific Severity of Fishery and Agricultural Communities
In depopulated areas dependent on primary industries, out-migration of young women is compounded by rising male non-marriage rates. Fishing and farming — physically demanding, financially uncertain — are often unattractive employment options for young women. The pattern of "increasing numbers of older and unmarried men in rural communities" further suppresses birth numbers through lost marriage and childbearing opportunities.
Reading the Structure
Black-hole cities absorb young people while suppressing birth rates, acting as a national accelerator of demographic decline.
The "black-hole municipality" concept defined by the Population Strategy Council captures the structural problem precisely. These are municipalities that attract large numbers of young women in-migrants but, because birth rates within their borders are low, contribute to national-level population decline. 21 of the 25 black-hole municipalities are concentrated in the Kanto region, including many Tokyo special wards.
The black-hole problem is a double structure. First, it accelerates the hollowing-out of source regions by drawing in young people. Second, by maintaining conditions in which those in-migrants do not or cannot give birth, it sustains low fertility at the destination too. Tokyo concentration involves a dual problem: raising the probability of disappearance for rural areas while Tokyo itself records a birth rate of 0.99 in 2022.
Critiques of the "disappearance" framing do exist. Nobunko has proposed the concept of "lively depopulation," arguing that small-scale communities can remain rich and viable. RIETI, reviewing 40 years of data, notes that population collapse has not occurred as rapidly as predicted.
Yet the structural seriousness of the problem does not diminish. Population concentration in Tokyo directly reduces rural birth numbers while also suppressing births at the destination. As long as this "national depopulation accelerator" function of major cities goes unaddressed, it will be difficult for the 744 at-risk municipalities to escape their classification.
Related Columns
- Tokunoshima TFR 2.25, Higashiyama 0.76 — Mapping Birth Rates Across 1,741 Municipalities
- Generational Pension Disparities Visualized by Birth Year
Related Guides
References
FY2024 Local Municipality Sustainability Analysis Report — Population Strategy Council. Population Strategy Council
40% of Municipalities 'At Risk of Disappearance': Young Female Population to Halve in 30 Years — Nikkei Shimbun. Nikkei Shimbun
Re-examining At-Risk Municipalities: What Does 40 Years of Data Tell Us? — RIETI. RIETI Special Report
Creating Lively Depopulation: A Perspective Beyond the Municipal Disappearance Theory — Nobunko Editorial Team. Rural Culture Association Japan
2024 Update: What Are At-Risk Municipalities? Challenges and Recovery Cases for 744 Municipalities — TURNS Editorial Team. TURNS
