The Instant Runoff Voting Patchwork: Handling Voter Errors and Ballot Length

As states and cities across the United States adopt instant runoff voting (IRV) in their constitutions and charters, they enact statutes and ordinances to implement this electoral system. IRV laws vary across jurisdictions, including by how many candidates they allow voters to rank and how they handle voters’ ballot-marking errors. These variations affect both the fraction of ballots disqualified due to voter error and whether an election’s winner is deemed to have earned a majority of votes. To maximize the number of ballots in the final round of tabulation and increase the odds of a majoritarian outcome, jurisdictions should consider adopting the IRV implementation rules proposed here: (1) allow voters to rank all candidates and (2) interpret overvotes, skipped rankings, and overrankings in the manner outlined within.