J-PAL affiliates Claudio Ferraz (Pontifícia Universidade Católica do Rio de Janeiro) and Frederico Finan (University of California, Berkeley) evaluated how exposing information about corrupt politicians impacted election results in Brazil. Taking advantage of a federal anticorruption program that randomly assigned municipalities to be audited, the researchers compared the electoral outcomes for mayors in two randomly selected groups of municipalities: those that were audited before and those that were audited after the 2004 election. This provided an opportunity to observe whether voters’ access to information prior to the election about politicians’ corruption levels affected vote share and reelection rates for incumbent mayors.
Municipalities audited before the elections with low number of corrupt violation were reelected, those with high number of violations were not.
In municipalities where two corruption violations were reported, the audit policy and the information release reduced the incumbent’s likelihood of reelection by 7 percentage points.
In municipalities where two violations were reported and a radio station existed, the audit policy and release of information reduced the incumbent’s likelihood of reelection by 11 percentage points.
When corruption was not found in a municipality with a local radio station, audits increased the likelihood that the mayor was reelected by 17 percentage points.
That is from a study conducted by J-Pal.