Discussion Paper

Interactions between Climate and Local Air Pollution Policies: The Case of European Passenger Cars

Dec 13, 2016 | Joshua Linn


Diesel fuel-powered vehicles typically emit more nitrogen oxides, which harm human health and the environment, than gasoline-powered passenger vehicles. Focusing on European new car markets, this paper analyzes the effects of vehicle taxes on emissions of carbon dioxide and nitrogen oxides.

Key Findings

  • Many European countries have recently adopted taxes that directly target passenger vehicle carbon dioxide emissions.
  • This paper analyzes the effects of the tax reforms on consumer choices, showing that the taxes reduce carbon dioxide emissions.
  • However, because the tax reforms increase the market shares of diesel fuel vehicles, they also raise nitrogen oxides emissions.
  • Fuel taxes would cause less of a tradeoff between carbon dioxide and nitrogen oxides emissions than vehicle taxes.


Several studies have found that taxing vehicle purchase or ownership on the basis of carbon dioxide (CO2) emissions reduces CO2 emissions. In this paper I show that CO2-based vehicle taxation can raise emissions of other pollutants that harm air quality and that the magnitude of this unintended effect depends on consumer substitution across and within gasoline and diesel fuel vehicles. Using data on European vehicle registrations, fuel prices, fuel taxes, and vehicle taxes from 2002 through 2010, I estimate the relevant substitution patterns and compare the performance of several empirical strategies based on the recent vehicle tax literature. According to the preferred specification, vehicle tax reforms have increased nitrogen oxide emissions, which harm local air quality. Moreover, fuel-based CO2 taxes introduce milder trade-offs between CO2 and nitrogen oxides emissions than do vehicle taxes.