Are Democracies Cleaner?

We inquire whether democracies enjoy lower pollution levels than autocracies by investigating the 'clean democracy hypothesis', which posits that democracies have a more demand-determined policy formation leading to more stringent environmental policies. We test this hypothesis with a large data set covering 137 countries and the period 1970-2012 using eleven different air pollutants as endogenous variables and a wide range of control variables measuring democracy, development stage, globalization, and factor endowments. We find no consistent evidence that democracies are cleaner, not even the richer ones, which casts doubt on the validity of single pollutants studies. Numerous checks show the robustness of our results.