Does smart city pilot improve green total factor productivity? Evidence from Chinese cities

In recent years, the construction of smart cities has gradually become an effective means of addressing urban economic and environmental challenges. Based on panel data of 249 Chinese cities from 2005 to 2020, this study uses a super-efficiency epsilon-based measure model and a Malmquist-Luenberger index to calculate the urban green total factor productivity (GTFP). Using the smart city pilot as a quasi-natural experiment, the time-varying difference-in-difference (DID) method is applied to determine the causal effect of smart city pilot on GTFP. Results show that smart city pilot increases urban GTFP in China, and a series of robust analyses have verified the reliability of the results. The heterogeneity analysis results show that the smart city pilot policy has a more significant positive effect on urban GTFP in the eastern and central regions, the high population group, and the high per capita GDP group. The mediating analysis further suggests that smart city pilot positively affects technological innovations and human capital which promotes urban GTFP. These findings are of great significance for smart city construction and coordinating the relationship between urban economic development and environmental protection.