Ballot Design and Electoral Outcomes: The Role of Candidate Order and Party Affiliation
We develop a causal inference model to study how designing ballots with and without party designations impacts electoral outcomes when partisan voters rely on party-order cues to infer candidate affiliation in races without designations. If the party orders of candidates in races with and without party designations differ, these voters might cast their votes incorrectly. We identify a quasi-randomized natural experiment with contest-level treatment assignment pertaining to North Carolina judicial elections and leverage double machine learning to accurately capture the magnitude of such incorrectly cast votes. Using precinct-level election and demographic data, we estimate that 12.0% (SE: 3.6%) of Democratic partisan voters and 15.4% (SE: 4.0%) of Republican partisan voters cast their votes incorrectly due to the difference in party orders. A placebo test using judicial races with party designations shows that the flip effect disappears when party affiliation is observable on the ballot, which is consistent with the proposed causal mechanism.
