The Impact of Input Rules and Ballot Options on Voting Error: An Experimental Analysis

Abstract

When election reforms such as Ranked Choice Voting or the Alternative Vote are proposed to replace plurality voting, they offer lengthier instructions, more opportunities for political expression, and more opportunities for mistakes on the ballot. Observational studies of voting error rely on ecological inference from geographically aggregated data. Here we use an experimental approach instead, to examine the effect of two different ballot conditions at the individual level of analysis: the input rules that the voter must use and the number of ballot options presented for the voter’s choice. This experiment randomly assigned three different input rules (single-mark, ranking, and grading) and two different candidate lists (with six and eight candidates) to over 6,000 online respondents in the USA, during the American presidential primary elections in 2020, simulating a single-winner presidential election. With more expressive input rules (ranking and grading), the distinction between minor mistakes and totally invalid votes—a distinction inapplicable to single‐mark ballots (1MB) voting—assumes new importance. Regression analysis indicates that more complicated input rules and more candidates on the ballot did not raise the probability that a voter would cast a void (uncountable) vote, despite raising the probability of at least one violation of voting instructions.

Usability of Ranked-Choice Voting Paper Ballots

“…One of the most important elements of this study was the errors that were observed. On RCV ballots, error can be categorized into “mismarked” and “void” ballots (Maloy & Ward, 2021). Mismarked ballots are those which have errors, such as selecting the wrong candidate, but the ballot is still able to be counted in the final tally.…”

“…Voting time is not the only consideration. Errors play a critical role in determining the overall usability of ballots – described previously as mismarked or void (Maloy & Ward, 2021). While void errors are critical, it is equally important to note that mismarked errors may result in a ballot that is unreflective of the voter’s intent.…”

“…While the Center for Civic Design (2017) shows that three rankings are sufficient for establishing basic RCV, this is highly contingent on the number of candidates. More candidates on a ballot introduces the need for more available rankings to prevent higher proportions of ballots from being exhausted before the tally is complete (Center for Civic Design, 2017). The format of paper ballots is important to the current systems of voting.…”