Research on the Impact of Environmental Protection Tax on the Efficiency of Urban Green Development

This study employs a quasi-natural experiment framework based on the policy shock of the 2018 Environmental Protection Tax Law implementation. Utilising panel data from 280 prefecture-level cities in China spanning 2010–2022, it comprehensively applies methods including the Difference-in-Differences (DID) approach and spatial econometric models to examine the policy effects of environmental protection tax on urban green development efficiency. Empirical findings indicate that the environmental protection tax significantly enhances urban green development efficiency, with this conclusion remaining robust after parallel trend tests and other stability checks. Mechanism analysis reveals that industrial structure upgrading serves as a key mediating pathway, while public environmental awareness exerts a positive moderating effect on policy outcomes. Spatial econometric results confirm that the environmental protection tax positively influences green development efficiency both locally and in neighbouring cities. The study offers insights for refining environmental taxation policies and promoting regional green coordination: synergies between industrial structure and public participation should be strengthened; differentiated policies should be implemented according to varying urban foundations; and regional linkage strategies should be formulated while accounting for spatial spillover effects.