The Causal Impact of Electoral Rules on Corruption

Abstract

The effect of electoral rules on political corruption has long been debated. While theoretical predictions are indecisive, empirical investigations overwhelmingly rest on cross-country comparisons or correlations, and therefore lack causal interpretations. In this paper, we address these issues by exploiting a specificity of the French electoral law which conditions the electoral rules for the election of municipal councils on municipalities' population size. Specifically, below 1,000 inhabitants, the system is a two-round individual majority system whereas above the threshold, the system is a two-round proportional list system. We leverage that discontinuity in a regression discontinuity design to measure the causal impact of switching from one voting system to another on the level of corruption of local representatives. Using survey and actual corruption data, we find that the proportional list system leads to higher levels of perceived and actual corruption.