Empirical Analysis of Cultural Infrastructure Investment in a Depopulating Society: A Full-Cost Accounting and Cost-Benefit Analysis of the Proposed 64.6 Billion JPY Sendai New Music Hall

This study examines the economic sustainability and social validity of the proposed Sendai New Music Hall project, which carries a total construction cost of 64.6 billion JPY. Utilizing the Regional Economy Analysis System (RESAS) for demographic projections, we perform a dual-layered evaluation through Full-Cost Accounting (FCA) and Social Cost-Benefit Analysis (CBA). The analysis incorporates field research on existing facilities—Tohoku University's Kawauchi Hagi Hall and Hitachi Systems Hall in Sendai—to verify actual demand. Our findings indicate a structural deficit exceeding 77 billion JPY over 24 years. Based on social discount rates of 1%, 4%, and 7%, the study identifies an optimal investment range of 1.0 to 3.0 billion JPY with approximately 2,000 seats. We conclude by quantifying the opportunity cost in terms of social welfare and alternative public expenditures.