Analysis of Air Pollution via Phase Difference

The fundamental assumption of analysing the association between urban air pollution and economic development is the negligible spread of air pollution between cities. The most existing studies mainly analysed the effect of economic development on a city's air pollution base on the assumption of negligible spread of air pollution. Hence, this paper aims to provide the statistical tools to verify the very assumption by performing the phase difference analysis on time series of air pollutants of cities in a region, particularly corresponding estimation and testing methods for the phase difference. Furthermore, the empirical analysis in the three regions of China shows that the main causes of air pollution are economic activities and weather conditions, and also the spread of pollutants between cities when the air pollution in a region is severe. This finding supports the existing conception of air pollution, specifically Environmental Kuznets Curve, and the need for a more extensive analysis allowing more detailed causes of the air pollution in a regression model.