Vanishing populations, contested futures: regional imagination, lexical convergence and policy translation in Japan’s ageing society

Demographic decline sharpens trade-offs between retaining working-age populations and sustaining foundational services in multiscale regimes that combine directionality with subsidiarity. We ask whether future-oriented local strategies converge in meaning or mainly in template-aligned language. Using a corpus of Japan’s national, prefectural and municipal strategies across phases, we measure lexical similarity (TF–IDF) and meaning-level alignment (semantic proximity). Vocabulary converges quickly, often via prefectural strategies, while semantic alignment is slower and weakly related to population change. The results show policy translation, not simple travel, and expose rhetorical compliance when indicator-led evaluation mistakes lexical convergence for substantive coordination.