Exhausted ballot
Ballot exhaustion in RCV
Critics of RCV bring the concept of Discarded Ballots (Exhausted Choices / Rankings) up as an important drawback in RCV.
Proactively and accurately explaining the challenge/drawback can help us to avoid buyer's remorse down the line (e.g. Maine repealed RCV and eventually brought RCV back again).
What does it mean that some ballot Choices / Rankings are Discarded / Exhausted (never considered in the final tally)?
A ballot becomes exhausted when a voter:
- Exhausted Choices: a voter can list their preferences such that when applied to a runoff round it is for a candidate who is already eliminated - the vote is taken out of the election
- Overvotes - example: voter accidentally ranks two candidates as their first choice
- Undervotes - example: voter ranks only one candidate on their ballot and that candidate is eliminated from the contest before the final round
This article of focusing on the first category "Exhausted Choices.
Ballot Exhaustion occurs when rankings on a voter’s ballot prevent their vote from being counted and determining the election’s end result. The ballot is discarded. These votes do not influence the final outcome.
Exhausted Choices
Ballot exhaustion occurs when a ballot is no longer countable in a tally as all of the candidates marked on the ballot are no longer in the contest.
An exhausted choice occurs when a voter ranks only candidates that are eliminated from a race.
For clarity - it is better to ignore overvotes and undervotes in the first round of tabulation as “exhausted votes” because voters could make the same mistake on a ballot in an election decided by plurality.
In other words, votes that are exhausted in the second and subsequent rounds of tabulation are purely a consequence of using ranked-choice voting method tabulation algorithm.
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Ballot exhaustion occurs when a ballot is no longer *countable* in a tally as all of the candidates marked on the ballot are no longer in the contest.
This can occur as part of ranked-choice voting when a voter has ranked only candidates that have been eliminated even though other candidates remain in the contest, as voters are not required to rank all candidates in an election.
In cases where a voter has ranked only candidates that did not make it to the final round of counting, the voter's ballot is said to have been exhausted. == ballot exhaustion occurs when all the candidates a voter ranked have lost even though two or more other candidates remain in the race. This might happen because a voter chose not to rank all or many candidates or because a voter ranked as many candidates as allowed on the ballot paper. Since such a vote contains no rankings of a candidate still in the race, it is allowed to exhaust and is no longer included in the tally for winner.
Exhausted ballots - who wins and loses in close races - if, for example, ten percent of ballots are exhausted, and the election margin was less than five percent, the winner may have a majority of all the non-exhausted votes, but not a majority of total votes counted in the first round.
This leaves open the possibility that some other candidate was the true majority choice -- and that, if voters who had their *ballots exhaust* were permitted to choose again, say in a runoff election among the two leading candidates, a different winner might emerge with a clear majority of votes cast in the runoff.
Although this is theoretically possible, it is unlikely. But it also is grounded in assumptions about runoffs that overlook of how much more likely it is to have “exhausted voters” in a traditional runoff than “exhausted votes” in an instant runoff. Runoffs usually mean that fewer voters have a meaningful say in the decisive election.
Scientific articles / studies
We analyze data taken from images of more than 600,000 ballots cast by voters in four recent local elections.
We document a problem known as ballot “exhaustion,” which results in a substantial number of votes being discarded in each election.
As a result of ballot exhaustion, the winner in all four of our cases receives less than a majority of the total votes cast, a finding that raises serious concerns about IRV and challenges a key argument made by the system's proponents.
Second, IRV does not ensure that the winning candidate will have received a majority of all votes cast, only a majority of all valid votes in the final round of tallying. Thus, it is possible that the winning candidate will fall short of an actual majority when a substantial number of ballots are eliminated, or “exhausted,” during the vote redistribution process. Third, and related to the previous point, there is some probability that a voter's ballot will become exhausted, eliminating their influence over the final outcome.
If at any point the voter did not rank a next choice (assuming her most favored choice or choices are eliminated), or all of the choices on the voter's ballot have been eliminated, the ballot is “exhausted” d meaning that it is excluded from future vote redistributions, and it does not affect the final outcome of the election. The ballot, in essence, is discarded. The process ends once a candidate receives a majority of the remaining valid votes.
See also
- spoiled ballots
- over-voted
- under-voted
- inactive choices
- disqualified ballots
- discarded ballots
- spent ballots
- wasted votes
links
- https://fairvote.org/rcv_elections_and_runoffs_exhausted_votes_vs_exhausted_voters_in_the_bay_area/
- https://ballotpedia.org/Ballot_exhaustion
- Ballot (and voter) “exhaustion” under Instant Runoff Voting: An examination of four ranked-choice elections
Legal challange: