Ballot Use with RCV
This section examines how voters interact with the ranked ballot, and how many voters end up electing a candidate they had ranked highly.
Ballot Error
All ballot types result in some number of errors in voting. In single-choice elections, ordinarily only overvotes - votes invalidated due to a voter attempting to vote for more than one candidate - count as ballot errors. In RCV elections, voters may make different kinds of deviant marks, including ranking the same candidate multiple times, skipping rankings, or including overvotes at later ranking orders. However, most of these do not impact the vote being counted as the voter intended. Only first-round overvotes can be fairly compared with errors in single-choice elections, since those are the only errors that, in both systems, invalidate the ballot entirely.
This section examines research into voter error as a measure of voter participation in the election process.
- A 2016 study by Professor David Kimball at the University of Missouri-St. Louis, and Ph.D. candidate Joseph Anthony, assessed the rates of “residual votes”, which include overvotes and undervotes, as a measure of both voter interest and voter error. The study shows that, in the 26 cities studied, the adoption of RCV was not associated with any change in the number of residual votes. Find FairVote’s one-page summary here and a working version of the Kimball and Anthony paper below.
Kimball, D & Anthony, J. October 2016. Voter Participation with Ranked Choice Voting in the United States.
- A 2015 study by Francis Neely and Jason McDaniel shows that overvotes (a type of voter error in which the voter selects too many candidates) are often more common in precincts with more African-American, Latino, elderly, foriegn-born, and less wealthy citizens. However, the pattern of overvoting is similar in both RCV and non-RCV contests. This suggests a need for greater voter education in general, rather than a larger cognitive burden stemming from RCV itself.
Neely, F & McDaniel, J. 2015. Overvoting and the Equality of Voice under Instant-Runoff Voting in San Francisco.
Inactive Ballots
Inactive ballots occur when a ballot cannot be counted for a candidate in the current round of vote tabulation. Inactive ballots are sometimes called “exhausted ballots”. A ballot can become inactive in the following ways:
- A voter chooses not to use all allowed rankings, and all ranked candidates are eliminated during the round-by-round tabulation. This is known as “inactive by voluntary abstention”.
- A voter uses as many rankings as allowed on their ballot, but nonetheless all ranked candidates are eliminated during tabulation. This occurs in jurisdictions which limit voters to fewer rankings than the number of candidates, such as allowing only three rankings. This is known as “inactive by ranking limit”.
- The voter makes an error which prevents their ballot from being counted. This is known as “inactive by error”.
Although voters should be permitted to rank as many choices as they want, they also have the right to abstain and not rank candidates beyond those they support. A non-RCV plurality election can be compared to an RCV election in which voters are limited to only one ranking. Consequently, ballots which are “inactive by voluntary abstention” are not a problem with RCV, but rather a problem that RCV helps to minimize by allowing voters to rank back-up choices.
FairVote analyzed all single-winner ranked choice voting races in the U.S. since 2004 and found that few votes become inactive due to either ranking limits or ballot error. Voluntary abstention is by far the most common source of inactive votes.
- For races with only 1 round of tabulation: Naturally, zero ballots become inactive between rounds of tabulation.
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For races with multiple rounds of tabulation: We have complete data for 89 single-winner races which used multiple rounds to determine a winner. For those 89 races, we found the following rates of inactive ballots.
- 7.7% inactive by voluntary abstention
- 3.4% inactive by ranking limit
- 0.08% inactive by error
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Total impact of inactive ballots in RCV races: When considering 1-round and multi-round races, the total impact of inactive ballots is as follows.
- 3.5% inactive by voluntary abstention
- 1.6% inactive by ranking limit
- 0.04% inactive by error
Outside research on inactive ballots:
- A 2015 study by Craig Burnett and Vladimir Kogan showed ballot exhaustion leading to winners elected without securing a majority of first-round votes. The authors correctly note that many exhausted ballots result from jurisdictions limiting the number of rankings to three.
Burnett, C & Kogan, V. 2015. Ballot (and voter) “exhaustion” under Instant Runoff Voting: An examination of four ranked-choice elections.
Read more on majority winners in the Who Wins RCV Races section.
Consensus Value:
We define "consensus value" as the proportion of voters who ranked the winner as their first, second, or third choice. We use consensus value as a measure of how much support the winning candidate garnered from the community as a whole. This measure is intrinsic to RCV and provides valuable information on how many voters found a winning candidate acceptable.
- Over 58% of winning candidates had the consensus of two-thirds of voters
- Over 30% of winning candidates had the consensus of three-fourths of voters.
- In all races for which we have enough data to determine consensus value, 67% of ballots ranked a winning candidate in their top three.
https://e.infogram.com/912863e4-2b19-4f6b-aa14-95f0a49cb66c?src=embedTestnoborder:none;allowfullscreen5505550
For more details on consensus value, see our spreadsheet of consensus values for single-winner RCV races.
