Research on the Impact of the Establishment of Cross-Border E-Commerce Comprehensive Pilot Zones on Environmental Pollution

In the context of the new development paradigm, accelerating global economic integration, and growing emphasis on trade growth and environmental protection, cross-border e-commerce and its comprehensive pilot zones (hereafter referred to as "pilot zones") play a pivotal role in promoting trade and exploring green trade models. This study employs a sample of 287 prefecture-level cities from 2005 to 2022 and utilizes the difference-in-differences (DID) model to examine the impact of pilot zone establishment on sulfur dioxide (SO₂) emissions. The results indicate that the pilot zone policy significantly reduces annual SO₂ emissions in these cities, primarily by enhancing green innovation. Heterogeneity analysis reveals that, in terms of resource endowment, the policy exerts a stronger emission-reduction effect on non-resource-based cities; geographically, it benefits the western region the most; and in terms of urban scale, large cities experience a more pronounced reduction. Based on these findings, this paper proposes targeted development recommendations for resource-based cities, the western region, and small- and medium-sized cities. It also advocates for promoting successful experiences, supporting green technology innovation, and improving the environmental supervision system to achieve coordinated trade and environmental protection, thereby contributing to global green trade transformation.