Household Environmental Kuznets Curves: Evidence from Passenger Transport Emissions

This paper uses detailed survey microdata to test whether a non-monotonic relationship exists between income and carbon dioxide emissions at the household level for passenger transport in the United States. Although the literature on economy-wide Environmental Kuznets Curves (EKCs) is vast, sector-specific analysis of household transport emissions is less common, is subject to considerable controversy, and is over a decade old in many instances, which does not account for recent trends in vehicle electrification and fuel economy. The analysis provides evidence of an EKC for household vehicle emissions, as emissions increase with income at lower levels but reverse for the highest-income households. Although this effect is statistically significant, the effect size is relatively small, since household emissions decline by 1.2% between the second-highest income households and the highest. This effect is the product of declining pollution intensities and activity levels at higher incomes.