Resumen
This paper investigates the effect of sulphur dioxide (SO2) and nitrogen oxide (NOx) emissions on the Total Factor Productivity (TFP) growth among 48 contiguous U.S. states, for the period 1965-2002. The relationship between TFP growth and emissions is examined using nonparametric econometric techniques that allow for the estimation of the elasticity of pollution for each state and each period and to account for possible nonlinearities in the data. The results indicate that both pollutants positively affect TFP growth. Moreover this effect is nonlinear. The average output elasticity for all states is 0.005 for SO2 and 0.04 for NOx emissions.