This paper investigates the income-pollution relationship within and optimal AK growth model with technological and ecological switches. We show that the EKC, that is usually seen as a description of the relationship between wealth and pollution along the different development stages of one country, can also emerge as a result of the implementation of the optimal policy from the current development stage of the economy.
Boucekkine, R., Pommeret, A., & Prieur, F. (2013). Technological vs ecological switch and the environmental Kuznets curve. American Journal of Agricultural Economics, 95(2), 252-260. https://doi.org/10.1093/ajae/aas048 (Original work published 2013)