Previous studies of income distribution have found evidence indicating that
incomes across U.S. regions have converged, supporting the prediction of t
he neoclassical growth model. A potential shortcoming in these studies is t
hat only one measure of well-being is considered-a measure of wealth linked
to incomes or production. This paper examines whether income convergence w
as accompanied by air pollutant emission convergence. Results from unit roo
t tests provide some evidence that indicators of environmental quality have
converged across U.S. regions during the 1929-1994 period.