Against the backdrop of China’s “dual carbon” goals and rising global uncertainties, new energy technology innovation plays a critical role in advancing low-carbon transitions and ensuring energy security. However, existing studies mainly focus on single policy instruments, with limited attention to the causal effects of comprehensive, location-based policies. This study treats the establishment of National Green Industrial Parks (GIPs) as a quasi-natural experiment and employs a multi-period difference-in-differences (DID) approach based on panel data from 289 Chinese cities over 2008–2023. The results show that GIPs significantly increase local new energy innovation by approximately 19.1%, and this effect remains robust across multiple tests. Mechanism analysis indicates that fiscal support, green innovation, and industrial agglomeration are the main driving channels. Heterogeneity analysis further reveals stronger effects in the biomass (ρ = 0.243, p < 0.01) and wind energy (ρ = 0.179, p < 0.01) sectors, as well as in cities located southeast of the Hu Huanyong Line, with higher fiscal expenditure, and in non-resource-based cities. These findings provide empirical evidence for optimizing industrial park policies and promoting energy transition through localized policy diffusion.
Dong et al. (Mon,) studied this question.