Social Pressure, Descriptive Norms, and Voter Mobilization

Several recent field experimental studies show that social pressure raises the likelihood of turning out to vote in elections. Ratcheting up social pressure to show subjects their own as well as their neighbors' prior voting history significantly increases the effectiveness of direct mail messages. A key component in stimulating this effect seems to be the presence of individual vote history. When voters are presented with less specific turnout information, such as vote history for the community at-large, the effects on turnout often dissipate. Sensitizing voters to such descriptive norms appears to do little to stimulate participation. To address this contrast, this study presents results from a voter mobilization field experiment conducted in Hawthorne, CA prior to the November 2011 municipal elections. The experiment is a fully crossed 2 x 3 factorial study in which subjects were randomly assigned to one of six conditions, in which they receive no mailing, a mailing with individual vote history only, a mailing with individual vote history and a message emphasizing high (or low) community-level turnout from a previous election, and a mailing emphasizing high (or low) community-level turnout only. County voter files were used to randomly assign voters to treatment and control and to report the effects of each mailing on voter turnout. We find that only messages that included information about subjects' own voting histories effectively mobilized them to vote.