The Future of Japan's Cities and Regions Under Population Decline

Introduction to a research project on population decline and regional extinction by RIETI Faculty Fellow Tomoya Mori, posted on August 8, 2025. Japan's population began declining in 2008, with IPSS projections indicating potential reduction to 30-50 million by 2120. In 2024, the Japanese population decreased by 910,000 and total population by 550,000, progressing at a pace equivalent to one prefecture disappearing annually. The birth rate fell to 1.15 in 2024, approaching IPSS pessimistic low projection of 1.13, making future recovery prospects difficult. Global population decline is also progressing, making substitution through immigration unlikely. He advocates the necessity of constructive shrinkage as sustainable policy 50-100 years ahead. Through a 7-part video series, this research is notable for comprehensively analyzing future visions of cities and regions using economic agglomeration theory and data, discussing everything from fundamental causes of population decline in family structures to social structural changes.