Analyzing the reductions in US air pollution emissions: 1970 to 1990

Findings of inverted-U relationships between income and certain pollutants have generated considerable controversy, yet relatively little is known: ab out the factors underlying these relationships. U. S. emissions of several major air pollutants have begun to decline, mirroring trajectories found us ing data across countries and time. We examine U. S. emissions of sir air p ollutants between 1970 and 1990, decomposing the changes into scale, compos ition, energy intensity, energy mix and other technique effects. Our result s provide a case study of the relative importance of these effects for a co untry on the downward-sloping portions of its emissions-GDP trajectories fo r the pollutants examined. (JEL Q25).