Election strategists across the world regularly use negative messages to influence voter behavior. Negative messaging is defined as any messaging that seeks to attack the candidate’s opponent, rather than make a case for the candidate themself. The research on negative messages shows that they have small but consistent effects on voter behavior. However, most of the existing literature has focused on hypothetical scenarios in laboratory experiments, or on stated intention to vote or donate based on the messaging received. There have been few attempts to study the impact of negative messaging on behavioral outcomes using a randomized controlled trial in a real-world setting.
This study was implemented during two local elections for county legislature during the 2010 general election in the U.S. Registered voters who had participated in the last 3 party primaries were randomly assigned into three groups—one to receive a positive message about the candidate, one to receive a negative message about the opponent, and one as control (which received no messaging). The messages were delivered by mail, and also provided the individual with the option of donating to the campaign. To test the efficacy of the messages and gather more information regarding their impact, the researchers also conducted a pre-experimental survey outside the districts chosen for the experiment. Using the survey, the researchers sought to understand whether the messages differed in terms of their informational content as well as their emotional impact on voters. The researchers measured both voter turnout as well as campaign contributions as dependent variables.
The researchers found that the impact of negative messages is mixed. Negative messages did elicit higher turnout compared to positive messages in both the districts where the experiment was run. However, neither form of message elicited greater contributions towards the campaigns. Further, by using a pre-experimental survey implemented outside the districts, the researchers show the negative messages are not more informational than positive messages. Thus, the improvement in turnout is not driven by information but might rather be linked to the tone of the negative campaign. Finally, by implementing the treatment several months before the election, the researchers were also able to provide evidence against the possibility that turnout increase is due to an emotional response, since an emotional effect is unlikely to persist for months.
The results have implications for how political candidates seek to gather campaign contributions. The study shows that there may not be a tradeoff between turnout and monetary contributions towards campaigns when exposing the voters with negative messages. This compares favorably to positive messaging, which sees a similar rate of monetary contributions while leading to a lower rate of “contributions” at the ballot box.