Is green place-based policy effective in mitigating pollution? Firm-level evidence from China

The green place-based policy is crucial for balancing economic competitiveness and environmental protection. However, there is scarce literature examining its impact on environmental pollution and the underlying mechanisms at the micro level. This paper treats China's National Demonstration Eco-Industrial Parks (EIP) as a quasi-natural experiment and systematically evaluates its effect on pollution using a difference-in-differences (DID) approach. With data from Chinese industrial firms and counties, this research reveals that the EIP leads to a significant reduction of 54.36% in firms’ sulfur dioxide (SO₂) emissions. Moreover, increasing R&D investment, reducing SO₂ emission intensity, implementing production process pollution control, and dynamic adjustments of firm entry and exit are significant influencing mechanisms. Heterogeneity tests indicate a stronger SO₂ reduction effect of the EIP program on firms in eastern regions, capital-intensive industries, and non-state-owned enterprises. This study suggests that the Chinese government should support the establishment of EIP, conduct a coordinate system, strategically plan the industrial chain, establish a pollution monitoring and early warning system, enhance information disclosure, and give greater emphasis to the construction of EIPs in central and western China.