Comprehensive innovation reform pilot zones and provincial green total factor productivity in China

China’s comprehensive innovation reform pilot zones (CIRPZs) provide a setting for examining whether innovation-oriented institutional reform is associated with provincial green total factor productivity (GTFP). This study uses a balanced panel of 30 mainland provinces from 2011 to 2021. Province and year fixed-effects difference-in-differences models are supplemented with event-study diagnostics, alternative timing checks, a document-coded local timing specification, a manual staggered-adoption diagnostic, selection-balancing checks and direct environmental-outcome regressions. The estimates remain statistically imprecise after controls, alternative timing assumptions and balancing checks. This lack of statistical robustness is a central result. Direct environmental outcomes are mixed: energy and CO 2 intensity estimates generally point in a greener direction but remain imprecise, whereas wastewater intensity increases in some specifications and SO 2 and smoke/dust results are unstable. Reconstructed DDF efficiency measures do not reproduce a strong positive CIRPZ association. The findings therefore provide suggestive, measurement-sensitive evidence rather than a precise causal estimate.