Synergistic policy effects of digitization in reducing air pollution and addressing climate change in China

Given the increasing constraints of climate change and air pollution on economic growth, constructing a comprehensive policy system that promotes the coordinated development of pollution reduction, carbon mitigation, and economic growth has become the key to resolving current contradictions. However, the synergistic effects of the policy combination between digitalization, pollution reduction and carbon mitigation remain insufficiently evaluated. Based on panel data from 239 Chinese cities spanning 2014 to 2024, this study employs a fixed effects model to comprehensively analyze the effects of atmospheric, climate, and digital policy combinations from multiple perspectives. The results indicate that the synergistic effects of policy combinations surpass those of single policies. In the case of single policies, they demonstrate synergy while effectively achieving policy goals. Regarding policy interactions, the interplay between two policies entails both complementary and substitution effects. When considering policy combinations, an appropriate number of policies can maximize the overall policy effect, while excessive combinations may trigger substitution effects between policies. From the perspective of policy actors, collaborative efforts among policy actors strengthen the synergistic effects of policies, though an increasing number of policy actors does not necessarily enhance the synergy. This study provides theoretical references for designing collaborative policy mechanisms and establishing a collaborative development policy network system.