The Impact of National Ecological Civilization Pilot Zone Policy on Rural Residents’ Income—Evidence from Chinese Counties

China’s National Ecological Civilization Pilot Zone (NECPZ) policy serves as a comprehensive policy for ecological and environmental sustainability that simultaneously enhances residents’ income. Using a panel dataset of 1761 counties in China from 2010 to 2022 and a staggered difference–in–differences (DID) methodology, this paper examines whether and through which mechanisms the NECPZ policy affects rural residents’ income. Our findings reveal that the NECPZ policy significantly increases rural residents’ income. The mechanism analysis indicates that ecological fiscal support, eco–industries’ development, and non–agricultural employment are crucial channels through which benefits are achieved. Furthermore, the NECPZ policy exhibits stronger effects in counties where rural residents have a lower income, suggesting its potential to mitigate income inequality. The income–enhancing effects also vary with local development conditions. Counties with higher agricultural endowments, stronger fiscal self-sufficiency, and greater entrepreneurial dynamism experience more pronounced gains. The NECPZ policy significantly increases rural residents’ income in the central–western regions, while the policy shows no positive effects in the eastern regions. These findings provide evidence on how the NECPZ leads to the growth of rural residents’ income, contributing to the design and implementation of ecological and environmental sustainability policies.