Previous studies have documented a positive association between election fraud and the
intensity of civil conflict. It is not clear, however, whether this association is causal or due to
unobserved institutional or cultural factors. This paper examines the relationship between
election fraud and post-election violence in the 2007 Philippine mayoral elections. Using the
density test developed by McCrary (2008), we find evidence that incumbents were able to
win tightly contested elections through fraud. In addition, we show that narrow incumbent
victories were associated with an increase in post-election casualties, which is consistent
with the hypothesis that election fraud causes conflict. We conduct several robustness tests
and find no evidence that incumbent victories increased violence for reasons unrelated to
fraud.