Do smart cities have lower particulate matter 2.5 (PM2.5)? Evidence from China

Abstract

• Smart city construction has reduced PM2.5 concentration in Chinese cities. • Smart city has spatial spillover effect on PM2.5 in non-pilot cities. • Smart cities reduce PM2.5 through technology effect and allocation effect. • The impact of smart cities on PM2.5 is heterogeneous. In recent years, smart city pilot policy has been effectively taken by the Chinese government for controlling its environmental pollution. Therefore, it is of great significance to reveal the effect of smart city construction on PM2.5 in China. Based on the panel data of China's 285 cities from 2004 to 2018, a difference-in-differences model was adopted to explore the impact, dynamic effect, spillover effect and influence mechanism of smart city pilots on PM2.5. We find that (1) smart city construction has reduced PM2.5 concentrations by 5.34%, and the reducing effect is increasing over time. The results remained valid after overcoming endogeneity problems and passing a series of robustness tests. (2) Smart city pilots have spatial spillover effect, which has a positive impact on PM2.5 of cities within 50km, while significantly reduces PM2.5 of surrounding cities within 50km-250km. (3) The PM2.5 reducing effect of smart cities is primarily the result of technological effect and allocation effect generated by promoting innovation and industrial upgrading. (4) The PM2.5 control effect of smart cities presents an inverted U-shape with the expansion of city size, and is better in cities with low levels of financial support, high levels of human capital and information infrastructure. Finally, this paper puts forward several brief suggestions.