The Impact of Climate Policy Uncertainty on Stock Price Synchronicity: Theoretical Mechanisms, Empirical Analysis, and Financial Market Response Strategies

Climate Change Policy Uncertainty (CCPU) constitutes a pivotal variable reshaping information efficiency in capital markets during the "Dual Carbon" transition. Utilizing China's A-share market as the research sample, this study integrates policy text analysis with corporate financial data to theoretically examine CCPU's transmission mechanism affecting stock price synchronicity (SYN) through the "information substitution effect," while empirically testing its heterogeneous characteristics and dynamic effects. Key findings reveal: CCPU significantly reduces SYN by exacerbating information asymmetry (β=-0.068***), with high-pollution industries (β=-0.070***) and large-scale enterprises (β=-0.074***) demonstrating heightened vulnerability due to policy sensitivity and information transparency, whereas highly leveraged firms exhibit attenuated sensitivity (β=-0.062***) buffered by debt servicing pressures. Dynamic models further unveil short-term policy persistence decaying through market memory mechanisms (SYN lag term β=0.312***). Accordingly, we propose tiered response strategies: policymakers should refine carbon price expectation management and green financial instruments, corporations must enhance low-carbon technology disclosure and capital structure resilience, while investors could hedge risks via ESG factors and derivatives. This research provides micro-level evidence for coordinating climate governance and financial stability, suggesting future extensions through cross-national heterogeneity comparisons, technical adaptability metric development, and integrated policy-digital technology simulation studies.