Assessing smart cities policy on urban green growth in China: The mediating effect of urban resilience

Using panel data of 280 cities above prefecture-level in China between 2003 and 2021, this paper estimates the urban green growth by the super-efficient SBM-GML model and assesses the impact of smart city policy (SCP) on urban green growth by utilizing the time-varying difference-in-differences (TV-DID) model. Additionally, this paper systematically examines the influence of urban resilience (UR) on green total factor productivity (GTFP), and elucidates the mechanisms through which UR affects both smart city development and GTFP using mediation analysis. The main findings indicate that: (1) SCP promotes GTFP by enhancing technological effects, allocation effects, and structural effects. (2) UR significantly improves a city's GTFP. Specifically, economic resilience fosters GTFP through technological progress and industrial upgrading, while social resilience contributes through green innovation. Ecological resilience improves GTFP through infrastructure development and government intervention, while infrastructure resilience helps alleviate labor mismatches and improve human capital, thereby promoting total factor productivity growth. (3) UR mediates the relationship between SCP and GTFP. (4) As revealed by heterogeneity analysis, SCP and UR on GTFP vary across regions, resource endowments, and city size. The policy effects in eastern regions are significantly stronger than those in the central and western regions; resource-based cities exhibit more pronounced effects than non-resource cities; and super-cities experience stronger policy effects than non-super cities. Finally, derived from empirical evidence, specific policy recommendations are outlined.