Economic growth and the environment: Theory and facts

Several recent papers propose competing theoretical explanations for the empirical observation of an inverted U-shape relationship between environmental degradation and per-capita income. We propose the following test of the theory: calibrate a theoretical model to an already developed economy using information unrelated to the pollution–income curve. Then simulate the model starting from a less developed initial condition and compare the predicted pollution–income relationship with that in the data. Our results are mixed. Some support exists for the theory that the inverted U-shape results from a corner solution in which less developed countries do not abate pollution. However, because we find abatement is relatively inexpensive, the model predicts pollution peaks at a level of per capita income much lower than that observed in our U.S. data. For some pollutants, we find evidence of a structural break in preferences in the early 1970s. When the structural break is added, the model performs better for two of three pollutants.