Depopulation and Regional Sustainability: Structural Transformation and Economic Resilience in Post‑Growth Japan

This study analyzes long‑term structural and demographic change in Japan by examining prefectural productivity trends from 1975 to 2021 and municipal‑level dynamics in Mie Prefecture. Four benchmark years—1975, 1989, 2006, and 2021—capture major turning points in Japan’s postwar economic trajectory. Spot values and interval‑based changes across the periods 1975–1989, 1989–2006, and 2006–2021 reveal three phases of regional economic development. Metropolitan prefectures led productivity growth until the early 2000s, but their dominance weakened after 2006, when productivity gains became concentrated in non‑metropolitan regions despite substantial population decline. Municipal‑level evidence from Mie Prefecture reinforces this pattern. Between 2011 and 2021, all 29 municipalities recorded increases in income per working‑age person, and municipalities with the steepest demographic contraction often showed the strongest income growth. These findings challenge the prevailing narrative of regional decline and indicate that depopulation may coexist with, or even facilitate, local economic restructuring. Overall, Japan’s regional transformation should be understood not simply as decline but as a process of reorganization driven by demographic change and the emergence of resilient local enterprises.