基于EKC的城市化和污水排放实证研究——以中国东部省际面板数据为例

An Empirical Study of Urbanization and Sewage Discharge Based on EKC: Taking Provincial Panel Data in Eastern China for Example

基于环境库兹涅茨(EKC)模型,以中国东部11个省(市、区)2006—2015年的污水排放为研究对象,用面板工具分析污水总排放、生活污水排放、工业污水排放分别与经济发展和城市化率之间关系。研究发现:首先,中国东部各省的污水排放与经济发展GDP、城市化率UR形成二元二次回归曲线;不同的排放与经济发展呈现不同的关系,但都与城市化率成线性回归。其次,经济发展和城市化率是生活和工业污水排放的单向的格兰杰原因,城市化和经济发展存在双向格兰杰原因,其变化直接导致污水排放的变化。再次,城市化率和经济发展对生活和工业污水排放的影响大小和方向不完全相同;城市化率对生活污水排放起到正向影响,对工业污水排放呈反向影响。最后,由于城市化率与经济发展的变化不完全相同,一定时期内污水排放模型呈现出的图形将会与污水排放和变化较快变量形成回归方程的趋势相近,这也解释污水排放与经济发展中还有其他形状图形的争议。

Based on the Environmental Kuznets Curve model,this paper takes the sewage discharge of 11 provinces( cities and districts) as the research object in eastern China,uses the panel data of from 2006 to2015 in all provinces and respectively analyzes the relationship among the total discharge, domestic sewage discharge, industrial sewage discharge and economic development with urbanization rate. The empirical results show that: first,the sewage discharge constitutes binary quadratic regression curve with economic development( GDP) and urbanization rate( UR) in provinces of eastern China. Different emission models have different relations with GDP,but they are linear regression with UR. Second,GDP and UR are the one-way granger causality for the discharge of domestic and industrial sewage. There is pairwise granger causalities for urbanization and economic growth and their changes directly lead to changes of sewage discharge. Third,there are different parameters of domestic and industrial wastewater discharge models which are related with urbanization rate and economic development. The urbanization rate has a positive impact on domestic sewage discharge and has a negative impact on industrial sewage discharge.Finally,because the change of urbanization rate is not identical with the change of economic growth, the graph of the sewage discharge model will be similar to the trend of the regression equation between sewage discharge and the rapidly changing variable within a certain period. It explains that other shapes dispute over sewage discharge and economic development.