The Impact Assessment of Eco-Industrial Development on Air Pollution: Evidence from China’s National Eco-Industrial Demonstration Parks

Eco-industrial development not only reduces pollutant emissions but also effectively addresses ecological and environmental pressures. Using panel data for 276 Chinese cities from 2006 to 2021, this study employs a Difference-in-Differences model combined with the Propensity Score Matching method to empirically examine the impact of eco-industrial development on air pollution, taking China’s National Eco-Industrial Demonstration Parks as the empirical setting. The analysis further includes robustness tests, heterogeneity analyses, and mechanism examinations focusing on green innovation and green investment. The results show that: (1) the establishment of National Eco-industrial Demonstration Parks significantly reduces PM2.5 emissions and improves environmental quality in host cities; (2) eco-industrial development mitigates air pollution by promoting green innovation and enhancing green investments; (3) the pollution reduction effect of eco-industrial development is more pronounced in central and western cities, industrial cities, open cities, and regions with lower levels of green development.