They have an interesting design, combining pre-election and post-election surveys and an exit poll–the former allow them to evaluate the impact of voting for the winner (or lower) on changes in perceptions of integrity.
The measures of integrity are are follows:
Our dependent variable measures citizens’ confidence in the integrity of the election. For the pre[post]-electoral survey, we use the following question: “In your opinion, how clean will [were] the presidential elections be [held last July 1st]?” Respondents chose among the following options: “Very clean,” “Somewhat clean,” “A little clean,” and “Not clean at all.” From the exit poll, we measure the voter’s confidence that her vote will be counted using the following question: “In general, how confident are you that the vote you cast for president will be respected and counted for the final result?” Respondents chose among the following options: “Very confident,” “Some- what confident,” “A little confident,” and “Not at all confident.”
The summary of findings are below. One note (not in the quote); the presence of election observers had no impact on perceptions of integrity.
On one hand, we show that confidence in the electoral process among supporters of the incumbent party decreased only after realizing that their candidate had lost. This change in the perceptions of electoral integrity responds to a pure “losers’ effect,” in which supporters of a losing candidate try to explain her defeat as a consequence of a poor electoral administration. On the other hand, we show that the discredit of electoral integrity among supporters of a party that has never won the presidential election is consistent over time. In this case, the skepticism from leftist partisans arose from both the systematic manipulation against left-wing parties during the twentieth century, and the dis- course of electoral distrust expressed by left-wing parties during recent presidential campaigns.
The full paper is available on early release.