Low-carbon city pilot policy and ecological efficiency of tourism: A quasi-natural experiment from China

China's Low-Carbon City Pilot (LCCP) policy is an important emission reduction measure, and its development is of great significance for enhancing the ecological efficiency of tourism industry. This study, for the first time at the urban level, adopts Difference-in-Differences (DID) and spatial DID models to systematically analyze the impact of the LCCP policy on ecological efficiency of tourism. The study effectively addresses the issue of endogeneity and reveals the spatial spillover effects and regional heterogeneity, providing new theoretical and policy foundations for the coordinated development of the environment and economy. The results show that the LCCP policy can significantly improve ecological efficiency of tourism, with this result remaining robust after a series of tests. This positive effect is more pronounced in western cities, while it is relatively weaker in central and eastern regions. Mechanism tests indicate that technological innovation and industrial structure optimization are the primary driving factors. Additionally, the policy has a significant negative spillover effect on the tourism ecological efficiency of surrounding areas. This research provides empirical evidence and policy insights for better utilizing the LCCP policy to promote the sustainable development of the tourism industry and lays the foundation for policymakers to design industrial incentive mechanisms that balance environmental protection and economic development.