Overvotes, Overranks, and Skips: Mismarked and Rejected Votes in Ranked Choice Voting

Abstract Voters express their electoral preferences through their ballot. More states and local jurisdictions are adopting ranked choice voting (RCV), which affects how voter preferences are translated into electoral results by introducing a more complex ranked ballot and accompanying tabulation process. This research provides empirical estimates of rates of improper marking and vote rejection, and compares them to those rates on non-ranked offices (particularly single-mark, ‘choose-one-candidate’ offices). We describe a new, general typology for categorizing the ways voters can improperly mark a ranked ballot. We apply this typology to a database of ranked choice ballots that includes 3 million cast vote records representing over three-quarters of all Americans living in a jurisdiction that uses RCV. The data show that in a typical ranked choice race, nearly 1 in 20 (4.8%) voters improperly mark their ballot in at least one way. We argue that these improper marks are consistent with voter confusion about their ranked ballot, and find evidence that this mismarking rate is higher in areas with more racial minorities, lower-income households, and lower levels of educational attainment. We further find that votes in ranked choice races are about 10 times more likely to be rejected due to an improper mark than votes in non-ranked choice races. These findings raise key questions about voter participation and representation in ranked choice systems and have important policy implications for jurisdictions that already have or are considering adopting ranked choice voting.