Uncovering the culprits of air pollution: Evidence from China's economic sectors and regional heterogeneities

The extensive and frequent occurrences of severe air pollution have aroused growing concerns from the public in China. However, we remain lack of understandings on the sources of air pollutants, which is exacerbated by the huge regional diversity across China. This study aims to identify the key sectors contributing to air pollutant emission and to test regional heterogeneity characteristics of air pollution in China, by incorporating a large number of sectors into investigation and probing with both national and regional perspectives. The partial least squares (PLS) regression is employed for reliable estimation. Three air pollutants, sulfur dioxide, nitrogen dioxide, dust emissions and 11 potential polluting sectors were investigated. Empirical results reveal several important findings. First, coal consumption, coke production, electricity production and car ownership are the top four contributors of air pollution in China. Second, coal consumption, flat glass and steel production are the most outstanding factors in the air pollution treatment key regions of China, including Beijing-Tianjin-Hebei region, Pearl River Delta, and Yangtze River Delta. Third, air pollution in non-key areas mainly sourced from coal consumption, coke production, and power generation. Fourth, considering the evident topography and geographical heterogeneities of air pollution in China, we find that cross-boundary flows of pollution externalities are important factors for air pollution in some regions. Based on the research findings, policy recommendations are provided to reap the far-reaching benefits of air pollution treatment.