Economic models for the environmental Kuznets curve: A survey

The 'environmental Kuznets curve' (EKC) refers to an inverted-U-shaped relationship between some pollutant level and per capita income, i.e., the environmental quality deteriorates at early stages of economic growth and subsequently improves at a later stage. Since the early 1990s, a considerable number of empirical studies have been conducted on the EKC and, although there is no conclusive proof, it has been recognized that the EKC emerges as an empirical regularity. However, some recent studies cast doubt on the concept and methodology of empirical results, and evidence of the existence of the EKC has been questioned. In fact, how economic growth affects the environmental quality (i.e. the shape of the EKC) is still controversial. In order to identify the actual relationship between the environmental quality and economic growth, it is essential to develop economic models from various points of view. This paper overviews the current stage of theoretical models that explain such relationship.