Standardization Governance and Urban Green Innovation: Evidence from China’s National Pilot Reform

Standardization acts as a key driver of governance and production efficiency, playing a crucial role in fostering green innovation. Treating China’s National Standardization Reform Pilot (NSRP) as a quasi-natural experiment, this study investigates this relationship using a staggered difference-in-differences framework on a panel dataset of 278 prefecture-level cities from 2012 to 2022. The empirical results demonstrate that the NSRP exerts a robust positive causal effect on urban green innovation, characterized by an inverted-U dynamic trajectory. Heterogeneity analyses reveal a pronounced non-monotonic size effect: the policy yields substantial innovation dividends for small and medium-sized cities but exhibits a null effect in large cities due to the potential crowding out of endogenous innovation. A moderated mediation model further establishes that the NSRP drives green innovation primarily by optimizing resource allocation efficiency and secondarily by stimulating regional innovation activity. Notably, the strength of intellectual property protection exerts asymmetric moderating effects, dampening the resource-allocation channel while amplifying the innovation-activity channel. This study provides rigorous empirical evidence that standardized governance acts as a critical catalyst for green transformation, offering valuable policy implications for tiered institutional design and optimal factor reallocation in developing economies aiming for sustainable growth. JEL Codes ：O31; Q55; Q58; R11