A simultaneous estimation of Environmental Kuznets Curve: Evidence from China

This paper uses Chinese provincial data from 1993 to 2002 to examine the existence of an Environmental Kuznets Curve (EKC) relationship between per capita income and per capita pollutant emission. Acknowledging the theoretical framework that economic growth and pollution are jointly determined, this paper starts from formulating a simultaneous equations model (SEM) to investigate the relationship between income and pollutant emission. A Hausman test is applied for income exogeneity and a two-stage least squares (2SLS) method is used to estimate the SEM. There are three main differences found between single polynomial equation estimators commonly used in EKC literatures and simultaneous equationa estimators. Since these differences tend to cause different policy implications, therefore, this paper suggests that the simultaneity between income and pollution should be considered before regressing the model in future EKC studies. In addition, this paper also investigates the determinants of income and government pollution abatement expense. Negative impact of pollution on income, and positive effects of physical and labor on income are found in income equation. Whilst positive effects of pollutant emissions, physical capital and the secondary industry share on pollution abatement expenses are also found in abatement equation.