Economic Growth and the Environment

Will the world be able to sustain economic growth indefinitely without running into resource constraints or despoiling the environment beyond repair? What is the relationship between steadily increasing incomes and environmental quality? This paper builds on the author's earlier work (1993), in which he argued that the relationship between economic growth and environmental quality – whether inverse or direct -- is not fixed along a country's development path. Indeed, he hypothesized, it may change as a country reaches a level of income at which people can demand and afford a more efficient infrastructure and a cleaner environment. This implied inverted-U relationship between environmental degradation and economic growth came to be known as the "Environmental Kuznets Curve," by analogy with the income-inequality relationship postulated by Kuznets (1965, 1966). The objective of this paper is to critically review, synthesize and interpret the literature on the relationship between economic growth and environment. This literature has followed two distinct but related strands of research: an empirical strand of ad hoc specifications and estimations of a reduced form equation, relating an environmental impact indicator to income per capita; and a theoretical strand of macroeconomic models of interaction between environmental degradation and economic growth, including optimal growth, endogenous growth and overlapping generations models. The author concludes that the macroeconomic models generally support the empirical findings of the Environmental Kuznets Curve literature. He suggests further empirical investigation related to the assumption of additive separability, as well as development of additional macroeconomic models that allow for a more realistic role for government.