RESUMO
This paper illustrates the direct and indirect effects of democracy on CO2 emissions in the BRICS countries (Brazil, Russia, India, China, and South Africa) from 1992 to 2018. In view of the distribution heterogeneity of CO2 emissions, the panel quantile regression model is especially used to explore the nexus among different variables. Furthermore, in order to predict the trends of CO2 emissions in different countries, we also estimate the kernel density function of CO2 emissions in the BRICS countries by the quantile-fitted values. The results indicate that the direct impact of democracy on carbon dioxide emissions is significantly negative and great at high-emission countries. Although the indirect effect of democracy is positive in China and negative in Brazil and South Africa, the total effect of democracy on CO2 emissions remains negative in all BRICS countries. The estimation of kernel density function shows that the distribution of CO2 emissions in each country is gradually concentrated. Moreover, there is an environmental Kuznets curve depicting the linkage of urbanization and carbon dioxide emissions in Brazil and South Africa. These findings further highlight that the impact of democracy on high-emission and low-emission countries should be taken into account in policymaking to achieve sustainable developments.