A forecast social return on investment analysis of a privately operated multi-purpose arena in Japan.

Japan is expanding arena development, yet the social value of privately financed multi-purpose venues remains under-examined. This study estimates the prospective social value of GLION ARENA KOBE, a privately financed and operated multi-purpose arena in Kobe, Japan, using a forecast Social Return on Investment (SROI) approach, and examines whether projected social value varies by residents' primary purpose of visit. A six-stage forecast SROI framework was applied prior to the arena's opening in April 2025. Data were collected through stakeholder interviews (n = 12), a resident willingness-to-pay survey (n = 500, of whom 250 were Kobe residents), and secondary financial projections to estimate inputs, outputs, and outcomes; the analysis is based on projected visitor numbers and anticipated outcomes rather than observed post-opening data. Projected annual inputs were ¥5.78 billion (USD 38.2 million) and anticipated outcomes ¥15.31 billion (USD 101.1 million), yielding a forecast SROI ratio of 2.65 in year one. When this total was distributed across residents' primary purposes of visit, concerts were the most frequently cited purpose (39.4% of the ratings recorded), corresponding to ¥6.03 billion of projected social value, followed by everyday park use (¥3.75 billion); event-related purposes together accounted for roughly three-quarters of the distribution, underlining the importance of both cultural programming and freely accessible public space. Sensitivity tests returned forecast SROI ratios of 1.45-3.25 across scenarios varying deadweight (15%-25%), attribution (10%-30%), displacement (5%-15%), projected resident visits (±20%), and the utilization rate (6.8-10.8%). Findings suggest that policy appraisal of arena developments should extend beyond economic multipliers to include outcomes such as civic pride, wellbeing, safety, and education, and that cultural programming alongside sport can enhance social returns where venues integrate quality public space. This study provides the first comprehensive forecast SROI of a privately operated multi-purpose arena in Japan, establishing a baseline for future evaluative SROI analysis; findings should be interpreted as prospective estimates subject to validation once actual operational data become available.