Abstract: Improving green economic efficiency is an essential step toward achieving sustainable development goals. In the context of China’s ongoing push for high-level opening-up, it is of significant practical importance to study the impact of trade liberalization on green economic efficiency. Based on the city-level data from 2006 to 2016, and using analytical tools such as word frequency statistics, instrumental variables, and threshold effect models, this study empirically explores the effects and mechanisms through which trade liberalization influences green economic efficiency. The findings show that trade liberalization has a significant positive effect on green economic efficiency, and this effect still holds true after robustness testing. The mechanism test shows that the green technological innovation and the agglomeration of producer services are key channels through which trade liberalization enhances green economic efficiency. The heterogeneity analysis reveals that the impact of trade liberalization varies significantly across regions. The expansion analysis indicates that the effect of trade liberalization on green economic efficiency exhibits non-linear characteristics, and high-level human capital and digital construction can provide guarantees for the release of positive effects of trade liberalization. Based on the above conclusion, while continuously promoting the process of trade liberalization, the government should accelerate digital construction, eliminate barriers to information flow, attach importance to the cultivation of high-quality talents, strengthen external knowledge absorption capabilities, so as to achieve a win-win situation between economic growth and green development through trade liberalization.

Key words: trade liberalization, green economic efficiency, human capital, digital construction