Using self-prophecy to combat vote overreporting on public opinion surveys

Survey researchers have long struggled with respondents who, due to the pressure to adhere to socially desirable norms, erroneously claim to have voted in a previous election. In this paper, we develop a new approach to reducing the overreporting of voting in surveys by leveraging psychological theories that show people have a tendency to follow through on an action once they have predicted their behavior (e.g. Sherman, 1980). Using a survey experiment through the 2014 Cooperative Congressional Election Study, we find that an overwhelming majority of respondents will agree to take an honesty pledge regarding their future vote report. Having pledged their honesty, they then overreport their vote at far lower rates than other survey participants. The observed effects are additive, since previously developed methods of reducing overreporting were present across all conditions. These findings have important implications for studies endeavoring to understand voting behavior and social desirability pressures.