The effects of election polls in Mexico's 2018 presidential campaign

This research note presents the results of an experimental design to study the effects of poll releases in Mexico's 2018 presidential campaign. Our research design allows us to test the conditions in which polling information can alter voters' reported preferences. The results show that the exposure to polling results makes respondents more likely to identify themselves as undecided. We interpret this change as a sign of voters' willingness to form veridical attitudes. To support this interpretation, we show that the effect is stronger among citizens with the ability and motivation to elaborate on the polling information. The findings contribute to the debate about the consequences of publishing pre-election poll results that show a clear advantage for one of the candidates.