Regional differences in spatial spillover and hysteresis effects: A theoretical and empirical study of environmental regulations on haze pollution in China

Haze pollution in China has increased the incidence of carcinogenesis, pathogenicity, and premature death. The challenge is to control it sustainably through environmental regulations (ERs), rather than a temporary “political blue sky.” The need to investigate the relationship between ERs and haze pollution, especially regional differences in ER spatial spillover and hysteresis effects on haze pollution, is urgent. Based on our proposed analytical framework, ER impact mechanisms on haze pollution were developed and empirically tested by static and dynamic spatial panel data models with province-level panel data from 2005 to 2015 in China. The results show that: (i) significant spatial autocorrelation exists for ERs and haze pollution, forming different aggregation clusters with dynamic evolution; (ii) ERs have strong spatial spillover and hysteresis effects on haze pollution; (iii) regional differences in spatial spillover effects verify that ERs show a linear growth relationship with haze pollution in the eastern region, an inverted “U-shaped” curve in the western region, and are ineffective in the central region; (iv) the hysteresis effect enhances ER effectiveness in the eastern region but weakens it in the western region. These findings will be of great significance for differentiated government-implemented management measures.