Green finance market development and carbon emissions trading: evidence on corporate environmental responsibility in China

From the perspective of institutional–financial synergy, this paper integrates environmental regulation theory with financial development theory to construct a theoretical framework for analyzing the effects of carbon emissions trading (CET) and green finance market development (GF) on corporate environmental responsibility (CER). Based on panel data of listed firms in high-carbon industries on China's Shanghai and Shenzhen A-share markets from 2010 to 2025, we employ staggered difference-in-differences (DID), moderating effect models, mediation effect models, and a moderated serial mediation model to examine their interaction and potential transmission channels. The findings are as follows. First, during the local carbon market pilot stage, treated firms' CER increased by 0.0214 on average, or 5.43% relative to the sample mean. When extended to the post-2021 period, the national carbon market estimates are consistent with a positive governance effect. Second, regional green finance development is significantly and positively associated with CER, and the CET × GF interaction is significantly positive, consistent with a synergistic complementarity interpretation. Conditional marginal effects show that the estimated CET effect is stronger when green finance support is higher. Third, the Bootstrap indirect effects of financing constraints, environmental information disclosure, and green technological innovation are all significant, consistent with three potential mediation channels. Fourth, the positive CET × GF interaction is stronger in state-owned enterprises, high-emission subsectors, eastern regions, and firms with higher executive environmental awareness. This study provides empirical evidence for optimizing the synergy between carbon trading policy and green finance policy and promoting corporate environmental responsibility.