Abstract:In the context of dual circular economy, based on the undesired super-efficiency SBM model, this paper calculates China's green total factor productivity (GTFP) from 2005 to 2019 under resource and environmental constraints, and uses the Theil index and its decomposition to investigate China's GTFP Finally, the impact of trade liberalization on GTFP was explored with the help of spatial econometric model. The results show that China's GTFP is at a low level as a whole, and the change in the mean value of GTFP from 2005 to 2019 is approximately "inverted-N". During the sample observation period, China's GTFP The overall difference shows a cyclic fluctuation trend of rising first and then decreasing. The difference between regions is decreasing year by year. The difference within the region is the first source of the overall difference in GTFP. Further spatial correlation test shows that China's GTFP has obvious spatial correlation, and the The blue index scatter plot shows the characteristics of high-high aggregation and low-low aggregation; the spatial econometric model shows that the impact of trade opening on GTFP is a positive promotion effect and a negative spatial spillover effect. Export trade has a promotion effect on GTFP in the region, and export trade has a greater promotion effect. Among the indirect effects, import trade has a negative spatial spillover effect on GTFP in neighboring regions, while export trade has a positive spatial spillover effect. There is heterogeneity. In the analysis of driving factors, urbanization level, economic development level and scientific research input water all have positive promotion effects on GTFP in the region, and the promotion effect of urbanization level is the largest. There is a positive spillover effect in adjacent areas, and the improvement of the level of economic development in this region may have a "siphon effect", resulting in the lack of human and resources in adjacent areas and hindering the growth of GTFP in adjacent areas.

Key words:trade openness ; green total factor productivity;SBM; spatial econometric