Heterogeneous and synergistic effects of environmental regulations: Theoretical and empirical research on the collaborative governance of China's haze pollution

The "30/60 target" of carbon emission peak and carbon neutrality proposes higher requirements for China's environmental management, emphasizing the importance of collaborative governance, rather than the "territorial trap" of unilateral environmental regulation (ER). Based on our analytical framework, the synergy of heterogeneous ER (SHER) was proposed and measured; thus, the heterogeneity and synergy mechanism of government-based (GER), enterprise-based (EER), and consumer-based (CER) ERs were developed and empirically evaluated, using spatial panel data models, with province-level panel data from 2005 to 2015 in China. The results are as follows: (i) Significant spatial autocorrelation was discovered for the SHER, which forms different agglomerations with a dynamic evolution of geographical distribution, especially in the low-low aggregation type. (ii) Significant heterogeneous impacts of GER, EER, and CER on haze pollution were found, that is, a "U-shaped" relationship, an inverted "U-shaped" curve, and a nonlinear association, respectively. (iii) A strong synergistic effect of GER, EER, and CER was verified, which greatly reduced haze pollution. (iv) A positive regulation effect of the SHER on enhancing the effectiveness of GER, EER, and CER was revealed, especially for CER, changing its impact from recessive to dominant. These findings provide a new perspective with theoretical and practical support for the management of air pollution.