How does digital trade impact urban carbon emissions efficiency? Evidence from China's cross-border e-commerce pilot zones

In the context of global warming and dynamically evolving economic circumstances, improving carbon emissions efficiency (CEE) has significant practical importance for addressing the dual challenges of economic development and the environmental protection in China. Currently, digital trade (DT) is a pivotal force driving CEE improvement in China; however, limited literature has explored the interconnection between these two elements. In this study, the application of the cross-border e-commerce pilot zone (CEPZ) policy serves as a quasi-natural experiment to analyze the impact of DT on CEE. The article implements a difference-in-differences approach with a panel dataset of 283 Chinese cities from 2005 to 2021. The results suggest that DT significantly contributes to enhancing CEE; a finding remains sound following several robustness tests like varying the sample size, dependent variables, and sample structure. The impact mechanism analysis reveals that DT has the potential to enhance urban CEE indirectly by influencing green technology innovation, industry clustering, and energy mix optimization. Heterogeneity tests indicate that DT may be more effective in fostering CEE in the eastern region, high-level cities, and nonresource-rich cities. Additionally, a noteworthy spatial spillover of DT extends to cities in close proximity to the pilot areas. The study's findings underscore the vital role of DT in improving CEE, providing empirical evidence to substantiate advocacy for sustainable economic development and the achievement of carbon peak and neutrality targets.