Spatial Spillover and Threshold Effects of the Digital Economy on Integration of the Cultural, Sports, and Tourism Sectors: Evidence from China’s Provinces

Digital transformation is reshaping resource linkages, service organization, and consumption scenarios among culture, sports, and tourism. Based on a balanced panel dataset of 30 Chinese provincial administrative regions from 2015 to 2024, this study constructs a culture–sports–tourism industry integration coordination index (CSTI) and a digital economy index (DE), and employs two-way fixed effects, a spatial Durbin model, a panel threshold model, and a quadratic specification to examine the average association, spatial spillover, threshold conditions, and regional heterogeneity of the relationship. The results show that (1) the digital economy has a significant positive association with CSTI, mainly operating through the comprehensive development component rather than the coupling component; (2) stable cross-regional spatial spillovers are not identified, indicating that digital connectivity does not automatically translate into regional coordination; (3) a threshold exists for economic development, but the marginal association weakens beyond the threshold rather than strengthening, and the human capital threshold is only marginally significant; (4) the central and western regions exhibit stronger DE coefficients, while higher initial digital infrastructure weakens the marginal effect; and (5) a significant concave relationship between DE and CSTI is found, but a strict inverted-U shape is not supported. These findings suggest that digital economy-enabled culture–sports–tourism integration is a locally embedded, conditionally dependent transformation process rather than a uniform, self-propagating linear growth path.