Toxic air pollutants and trucking productivity in the US

This paper introduces toxic air pollutants into the measurement of trucking productivity to obtain true productivity growth. Our results show that omitting or ignoring toxic air pollutants in measuring trucking productivity yields statistically significant biased productivity estimates in for 2002–2005. Trucking productivity growth was understated by the traditional productivity measure, because the latter did not account for reductions in truck air pollution over time. We also find that the difference between traditional and environmental efficiency scores was negligible, suggesting that environmental constraint did not distort efficiency in the trucking sector.

► Traditional productivity estimates for years 2002–2005 were downward biased.
► Traditional measure underestimated growth by 4.4% points.
► Main source of productivity growth was technological progress.
► Efficiency change was stagnant over time.
► Difference between traditional and environmental efficiency scores was negligible.