Overtourism and Local Environmental Responsibility: Nonlinear Effects of Tourism Demand with Metropolitan-Area Moderation Across Municipalities in South Korea

This study examines how rising tourism demand reshapes residents’ environmental responsibility behaviors (ERB) in South Korea, and the moderating role of metropolitan status therein. Using a balanced panel of 174 municipalities over 2015–2023, semi-log regression with a quadratic tourism-demand term and Driscoll–Kraay standard errors is applied to address heteroskedasticity, autocorrelation, and cross-sectional dependence. The estimates show that tourism demand displays a positive effect on ERB (a 6.6% increase in recycling volume proxy per million visitors) up to a certain threshold, beyond which the influence reverses—consistent with an inverted U-shaped relationship under overtourism. Turning points are approximately 11.06 million visitors for non-metropolitan municipalities and 6.95 million for metropolitan ones, where saturation occurs earlier. The negative interaction between metropolitan status and the squared tourism-demand term indicates that the erosion is sharper in metropolitan areas. Among controls, inbound visitor share (+2.8%), regional population (+3.6% per ten thousand residents), resident cost-sharing ratio (+0.4%), tourism special zones (≈1.45 times non-designated areas), tourism complexes (+19.2%), and COVID-19 intervention (≈1.30 times pre-pandemic) are significant, while the fiscal self-reliance ratio exhibits a small adverse impact. These findings suggest tourism policy should favor demand-management over growth-oriented strategies, aligned with regional structural differences and community-based environmental governance.