The Effect of Income Inequality on SO2 and SPM Emissions

In recent years, many policymakers and researchers have considered environmental degradation and pollution, as an international challenge. However, income inequality significantly affects the quality of the environment through social demand and can be important in policymaking. Income inequality, as a relative effect, also causes environmental degradation by changing the preferences of consumers of public environmental goods. This study investigated the effect of income inequality on SO2 and SPM emissions for the period 1990 to 2018 in the form of Johansen's approach. The results show that Gini coefficient has a positive and significant effect on SPM and SO2 emissions, so that one percent increase in Gini coefficient can effect 1.29 percent increase in SPM emissions and 1.37 percent increase in SO2 emissions. Based on the estimated results, energy consumption has a positive effect on SPM and SO2 emissions in Iran. So, one percent increase in energy consumption, 1.12 percent increases SPM emissions and 1.44 percent SO2 emissions. Economic growth has a positive effect on the release of SPM and SO2 in Iran. One percent increase in economic growth increases 0.78 percent of SPM emissions and 0.79 percent of SO2 emissions. According to the coefficient table the variable Ly2 is negative. Therefore, the Kuznets environmental curve hypothesis cannot be rejected during the period under study. Urbanization has a positive and significant effect on SPM and SO2 emissions, so that it increases one percent increase in urbanization, 0.93% SPM emissions and 0.97% SO2 emissions.