Differential Emission Reduction Effects of Pollution and Carbon Reduction Policies from the Perspective of Fiscal Decentralization: Evidence from China

Addressing the urgent need for air pollution and carbon emission reduction and the uncertainty in local policy implementation under fiscal decentralization, this paper quantifies the intensity of various pollution and carbon reduction policies and examines their effects on carbon–air pollution reduction, as well as their heterogeneity across different dimensions and levels of fiscal decentralization. Findings: (1) Policies overlap significantly, focusing on industry, construction, transport, agriculture, industrial parks, and rural areas. (2) Policies aimed at improving air quality, reducing carbon emissions, managing solid waste, and handling hazardous waste are associated with significant reductions in carbon–air pollution emissions, with carbon emission reduction policies being the most notable. In contrast, water pollution control, soil and groundwater pollution control, and comprehensive policies showed no statistically significant synergistic effects on carbon–air pollution reduction. (3) Fiscal decentralization has a complex moderating role on the carbon–air pollution emissions reduction effectiveness of policies, and this effect varies depending on the dimension of decentralization, the level of decentralization, and the type of policy.