A revisit of the EKC hypothesis in top polluted African countries via combining the ARMEY curve into the Kuznets curve: A Fourier ARDL approach

The present research reexamines the validity of the EKC hypothesis in the top three polluted nations in Africa, Algeria, Egypt, and South Africa, over the period 1970-2020. The central idea of the research is to reexamine the EKC hypothesis by incorporating the ARMEY curve linking government spending and GDP into the Kuznets curve, as suggested by Isik et al. Environ Sci Pollut Res 29(11):16472-16483, (2022) and Ongan et al. Environ Sci Pollut Res 29(31):46587-46599, (2022). To this end, the ARDL equation with a Fourier function is implemented to estimate the long-run drivers of environmental deterioration. The Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model results revealed that the composite model is only valid in Algeria, and the optimal government spending that maximizes CO2 emissions is 16.88% of gross domestic product. On the contrary, the results showed that the composite model is not valid for South Africa and Egypt due to the failure of the desired shapes for the three curves. The outcomes also confirm the role of energy consumption and population as key drivers of environmental degradation in the three countries.