Does the opening of China railway express promote urban total factor productivity? New evidence based on SDID and SDDD model

As a new path for the Chinese government to deepen reform, expand opening up and promote economic development, the opening of CRE may have an important impact on urban total factor productivity. Based on the panel data of 276 prefecture level cities in China from 2006 to 2018, the SDID and SDDD models are used to empirically test the impact of the opening of CRE on urban total factor productivity. The results show that the CRE significantly promotes the total factor productivity in both opening and neighboring cities. The mechanism test shows that the CRE promotes the total factor productivity of the opening cities through external effects and synergy effects, and promotes the total factor productivity of neighboring cities through spatial spillover effects and synergy effects. Regional heterogeneity shows that the improvement effect of the CRE on total factor productivity is mainly reflected in coastal opening cities, inland opening cities and inland neighboring cities. Therefore, this paper suggests that domestic cities should seize the development opportunities of the CRE and fully release the scale effects and spatial spillover effects. At the same time, the CRE should accelerate the formation of efficient collection and distribution system, and enhance the external effects and synergy effects on urban total factor productivity.