Eco-industrial parks and green technological progress: Evidence from Chinese cities

In this paper, the impact of national eco-industrial parks (EIPs) on green technological progress is assessed, with a focus on Chinese cities. Staggered difference-in-differences is used to analyze panel data from 314 prefecture-level cities in China from 2002 to 2017, and the results show that EIPs significantly increase green technological progress. Various robustness checks, including the use of event study, Oster omitted variable detection, and relevant city slope as instruments, corroborated the robustness of this finding. The research expenditure intensity, scale agglomeration level, and industrial structure optimization are channels with which EIPs stimulate green technological progress. Further, it is demonstrated that heterogeneity (with an inverted U-shape) exists between the green innovation effect of EIPs and the city scale.