The Impact of Carbon Information Disclosure on Firm Value: The Mediating Role of Green M&A—Evidence from China

Under China’s “Dual Carbon” strategy, carbon transparency has become a critical determinant of corporate competitiveness. Using a dataset of Chinese A-share listed companies from 2010 to 2023, this study constructs an integrated theoretical framework combining signaling theory and the “real effects” hypothesis to investigate the impact of carbon information disclosure (CID) on firm value. The results demonstrate a significant positive relationship between CID quality and firm value, a finding that remains highly robust against the exogenous macro-policy shock of the 2020 Dual Carbon goals. A primary conceptual contribution lies in identifying Green Mergers and Acquisitions (M&A) as a vital mediating strategic mechanism. High-quality CID acts as a credible commitment device that triggers internal problemistic search, compelling firms to undertake substantive green M&A to fulfill environmental claims, thereby establishing a “transparency-to-strategy-to-value” continuum. Furthermore, heterogeneity analysis indicates that the valuation premium is markedly more pronounced in non-state-owned enterprises (Non-SOEs) and non-heavily polluting industries, reflecting their reliance on transparency to alleviate capital constraints and signal “green competitiveness.” These findings confirm that the capital market prices carbon disclosure as a high-quality strategic asset rather than a mere compliance cost, offering targeted empirical evidence for policymakers to refine standardized disclosure frameworks and for investors to screen for substantive “Green Alpha.”