The environmental Kuznets curve posits an inverted-U relationship between pollution and economic development. Pessimistic critics of empirically estimated curves have argued that their declining portions are illusory, either because they are cross-sectional snapshots that mask a long-run "race to the bottom" in environmental standards, or because industrial societies will continually produce new pollutants as the old ones are controlled. However, recent evidence has fostered an optimistic view by suggesting that the curve is actually flattening and shifting to the left. The driving forces appear to be economic liberalization, clean technology diffusion, and new approaches to pollution regulation in developing countries.
"Confronting the Environmental Kuznets Curve." Journal of Economic Perspectives,