Can the establishment of eco-industrial parks promote urban green innovation? Evidence from China

Eco-industrial parks (EIPs) are important for promoting urban green innovation (GI) and achieving green and sustainable development. However, there is a lack of research on the impact of pilot national EIP policies on regional GI in China. Based on Porter's hypothesis and agglomeration economy as the theoretical basis, this study uses a time-varying difference-in-difference (DID) model and panel data of 264 prefecture-level cities in China from 2003 to 2018 to investigate the impact of the establishment of national EIPs on the GI of the cities where they are located. The results indicated that the establishment of national EIPs had a significant positive impact on the GI of local cities, which was mainly realized through the mechanisms of technological innovation, industrial structure upgrading, and human capital agglomeration. In addition, the results of heterogeneity tests demonstrated that the eastern region and cities with high administrative levels gained the greatest policy benefits from the pilot establishment of EIPs. These findings provide a foundation for further optimizing and promoting the construction of EIPs.