Does intellectual property protection policy always promote green development in firms? Evidence from China

Green development (GD) has gradually become a central theme of the current era, yet the role of intellectual property protection (IPP) in this process remains insufficiently clarified. Using a dataset of 19,505 observations from Chinese listed companies between 2003 and 2021, we conduct an empirical analysis based on a multi-period difference-in-differences (DID) model. The results indicate that the implementation of IPP policies significantly promotes corporate GD, and this conclusion remains robust after a series of tests, including parallel trend tests, placebo tests, PSM-DID estimation, alternative dependent variable measurement, sample-period adjustment, and clustered standard error checks. Mechanism analysis reveals that IPP policies enhance corporate GD through two key channels: technology transfer and innovation quality. R&D investment helps improve the effectiveness of IPP policies. However, overly strong IPP and excessively open corporate environments may weaken the effective implementation of such policies.