Temporal Misalignment of Planning Horizons and the Relative Positioning of Demographic Assumptions in Japan’s Ordinance-Designated Cities: Implications for Public Facility Management

This paper presents a descriptive and exploratory analysis of temporal mismatch between Comprehensive Management Plans for Public Facilities (PFMPs) and other municipal management plans, and of the positioning of population assumptions against a common external benchmark, focusing on Japan’s 20 ordinance-designated cities. Using the PFMP as the reference plan, Mismatch Years and Mismatch Ratio are treated as risk indicators of potential coordination exposure, while DOG (annualised) is used as the primary indicator of demographic assumption positioning. Descriptive tabulations show that the average PFMP duration (20.80 years) exceeded those of the Basic Plan (10.00 years), Fiscal Vision (7.65 years), Administrative Management Policy (7.95 years), and Implementation Plan (4.30 years). Most cities projected population decline, although assumed levels varied considerably. Spearman correlations between DOG (annualised) and Mismatch Ratio were weakly negative for the Basic Plan, Fiscal Vision, and Administrative Management Policy, with no clear positive monotonic co-movement. These results suggest that temporal mismatch and demographic assumption positioning are analytically distinct governance dimensions. Policy implications include synchronising PFMP reviews with medium-term fiscal and administrative cycles, rechecking demographic assumptions against a common external benchmark, and stress-testing PFMP assumptions across multiple crisis scenarios.