人口集聚对雾霾污染的空间溢出效应及门槛特征

集聚理论认为，人口集聚可能通过外部性影响雾霾污染的变化，而且由于空间的异质性使得传统的空间同质性假设难以表述二者复杂的非线性关系.因此，该文选取2003年—2016年中国202个地级市的面板数据，采用空间面板杜宾模型和面板门槛模型实证检验人口集聚与雾霾污染之间的非线性空间关系.研究表明：1)人口集聚对雾霾污染存在明显的空间溢出效应，并且区域间的溢出效应大于区域内的效应.2)人口集聚对雾霾污染的影响存在门槛特征，在跨过门槛值3.961之前，人口集聚会加剧雾霾污染；在跨过门槛值之后，人口集聚对雾霾污染的影响出现边际递减现象.由此，提出政府需要制定科学的联防治霾政策、重点关注人口集聚对雾霾污染的空间溢出效应、灵活处理人口集聚对雾霾污染非线性关系的政策建议.

Spatialspillover effect and threshold characteristics of population accumulation on haze pollution

The agglomeration theory holds that population agglomeration may affect the degree of haze pollution through externalities， and because of spatial heterogeneity， the traditional spatial homogeneity hypothesis is difficult to express the complex nonlinear relationship between the two. Therefore， this paper selects the panel data of 202 prefecture-level cities in China from 2003 to 2016， and uses the spatial panel Dubin model and the panel threshold model to empirically test the nonlinear spatial relationship between population agglomeration and haze pollution. The res show opulation agglomeration has obvious spatial spillover effect on smog pollution， and the spillover effect between regions is greater than the effect within the region. The impact of population agglomeration on smog pollution has the threshold characteristics. Before crossing the threshold value of 3.961， population gatherings aggravate smog pollution； after crossing the threshold， the impact of population agglomeration on smog pollution appears marginal decline. Therefore， it is proposed that the government needs to formulate a scientific joint prevention and control policy， focus on the spatial spillover effects of population agglomeration on smog pollution， and flexibly deal with the policy recommendations on the non-linear relationship between population agglomeration and smog pollution.