Approval voting is a voting method in which voters may vote for as many candidates as they choose, or “approve” of. The winner is the candidate with the highest number of votes or “approvals."
While easy to execute, approval voting has rarely been used and is explicitly prohibited in the many states that invalidate a ballot with an “overvote” (a ballot in which a voter has voted for more candidates than winners).
A "compromise" form of approval voting tried in St. Louis adds a traditional runoff after the first round of voting, but that system - just like any runoff system - is nonmonotonic and is even more problematic than runoff elections for allowing a small primary electorate to control choices in the higher turnout general election.
Votes for a back-up choice can harm your first choice in approval voting.
Approval voting can be challenging for voters who have strong preferences between candidates. A vote for a second choice counts exactly as much as a vote for a first choice, creating incentives to “bullet vote”, or choose only one candidate, even for voters who have second- or third-choice preferences. The fact that a voter cannot back a compromise candidate without hurting their first choice means that in contested elections that matter, strategic voting becomes key and most voters will not vote for more candidates than winners.
In RCV, a voter’s ranking for a backup choice only counts if their first choice is defeated, eliminating the incentive to bury support for a second-choice candidate.
Approval voting rewards strategic/savvy voters.
Savvy voters who have the most robust understanding of approval voting strategy can ensure their vote is highly impactful, while other voters may miss out. If a voter knows which candidate is likely to be the biggest threat to their favorite candidate, the savvy voter will know they can bury support for the competitor to boost the chances of their favorite candidate, regardless of their sincere preferences. This, ironically, means less nuance and fewer back-up choices on the ballot. A voter's inability to distinguish between strong support and weak support in approval voting naturally leads to strong incentives to vote strategically rather than honestly, putting voters on uneven footing.
Approval voting does not always elect candidates with broad support.
Even if voters are willing to vote for multiple candidates, already a stretch to imagine, winning candidates in a large field can win with low overall support from the electorate. In one of the few places to try approval voting in elections where the results are reported, Dartmouth College students got rid of approval voting after a string of student presidents elected with support from less than 40% of voters. The same pattern has been true in student elections at the University of Colorado, where typically more than 90% of voters vote for one candidate.
Approval Voting Can Elect a Candidate With No "First Choice" Support
Approval voting can result in victory for a candidate with zero supporters who would select that candidate as their top choice over over a candidate that more than half of voters support as their first choice.
Candidates who win RCV elections must have a strong base of first-choice supporters in addition to breadth of support.
Approval voting might not elect a majority-preferred candidate.
Because voters are unable to distinguish between strong support and weak support on their ballot, it’s possible that a candidate whom well over half of voters prefer as their top choice could lose to a candidate with little-to-no first-choice support.
RCV has a demonstrated track record of improving representation for women and people of color.
Unlike in ranked choice voting elections, there is no sustained evidence that approval voting would benefit these groups.
The Courts and Approval Voting
Approval voting has such limited use in governmental elections that it has never come before a judge. Given that voters transparently are using an uneven number of votes and that a candidate with 51% first choice support can lose a mayoral race to a candidate with no first choice support, approval voting advocates will need to be ready to defend the system based on federal and state constitutional provisions relating to the right to vote.
Subjectivity of Preference in Approval Voting
Different voters may interpret “approval” in different ways, giving them different amounts of power over the election outcome. For example, one voter may interpret it as only voting for candidates they actively like. Another voter may instead vote for all candidates who they find at-all palatable. These voters now have different levels of impact on the outcome of the election because they are inconsistent in how they express their preferences. Just as rating a film on a scale from “thumbs up” to “thumbs down” is highly subjective, rating candidates in the same manner is likelier than RCV to yield inconsistent returns.
Approval voting has not been used in a single-winner context for public government elections anywhere in the world. Two U.S. cities have used multi-winner approval voting or modified approval voting for multi-winner contests: Fargo (ND) in 2020 and St. Louis (MO) in 2021.
St. Louis adopted a modified version of approval voting in 2021, using approval voting for the first round of a two-round runoff election. Results were mixed. In the mayoral preliminary election, voters voted for an average of 1.6 candidates to determine the two winners who would advance, high for a typical single-winner election but low for a two-winner election. This was true even though the leading newspaper endorsed two mayoral candidates, and voters knew they could more safely vote for two candidates because two candidates would advance.
The result is that during the general election in which turnout was 30% higher, voters were presented with only the two choices identified by approval voting from the primary electorate, rather than seeing a full spectrum of choices at the time when turnout is highest. Professor David Kimball of the University of Missouri-St. Louis found that voters in majority-White wards were more likely to engage with approval voting by casting multiple votes than voters in majority-Black wards. This likely means that White voters had a larger impact on determining the two finalists than Black voters.
St. Louis also used approval voting for the first round of seven city council elections in 2021. In those contests, voters “approved” an average of 1.1, 1.1, 1.2, 1.1, 1.2, 1.4, and 1.1 candidates. This dismal rate of ballot usage may be a reflection of voters’ unwillingness to support second-choice candidates when that support can harm the chances of their first-choice.
Three of the city council runoffs elections resulted in different winners than the leaders from the approval voting preliminary elections which limited the field to two. Most notably, the approval voting “winner” in Ward 17 earned approval votes from 69% of voters over 46% for the second-place candidate, yet lost the head-to-head runoff.
In Fargo, multi-winner approval voting was first used in 2020 to elect two city councilors. Both winners had majority support and voters used an average of 2.3 “approvals” per voter in a field of seven candidates.
Private Experiments with Approval Voting
In addition to the two cities above, a number of parties, universities, or private organizations have used approval voting and later replaced it. The Independent Party of Oregon held an online primary in 2016 using approval voting but the party reported that over 70% of participants bullet-voted for only one candidate. The party discontinued use of approval voting in favor of STAR voting, with which they also experienced mixed results.
Similarly, Dartmouth University used and repealed approval voting for both Alumni Association trustee elections (repealed by alumni in 2009 by 82% - 18%) and for student elections (repealed in 2017) after patterns of non-majority winners and strategic bullet-voting. The largest association to try approval voting, the Institute of Electrical and Electronics Engineers (IEEE) repealed approval voting and reported that more than 80% of voters had been voting for only one candidate.
Ultimately, we conclude that in many cases, the strong incentive to bullet-vote in approval voting elections results in a lack of voter engagement with the ballot, meaning approval voting does not guarantee the promise of delivering better outcomes than plurality elections.
Consider an election in a region which is heavily skewed towards one faction. 60% of voters prefer faction A, while 40% prefer faction B.
In an approval voting election, half of the faction A voters (30% out of 60%) vote for the candidates of their own party, as well as the Independent candidate who they believe they can live with. The remaining faction A voters interpret approval voting differently and they vote only for candidates they genuinely like, rather than candidates they could live with. They only vote for candidates from faction A.
The voters aligned with faction B vote for the faction B candidates and the Independent, understanding that the Independent is their best chance to defeat the majority faction.
|Number of Voters||Preferences||Approval Voting Behavior||RCV Behavior|
Prefer faction A;
oppose faction B
Half vote for A and I
Half vote for A only
Half rank A, I;
Half rank A
Prefer faction B;
oppose faction A
|Vote for B and I||Rank B, I|
neutral between A and B
|Vote for I only||Rank I|
In an approval voting election, the votes would be counted as follows:
The independent candidate wins the approval voting election, even though there is a strong majority preference for faction A. This is a non-majority outcome.
The minority factions will be very satisfied with this result, as the 10% Independent voters get their top choice, and the 30% faction B voters were able to deny a victory to their chief opponents. However, 60% of voters will be disappointed in this result. In an election like this, faction A voters have a strong incentive to bury support for any candidates other than their absolute favorite because of approval voting’s inability to differentiate between strong support and weak support. Faction A voters in the election above could secure a more desirable outcome for the majority of voters by denying votes to the Independent. Ultimately, the faction that best understands the strategic incentives behind approval voting will be able to gain a significant advantage over less-savvy voters.
In a ranked choice voting election, elimination rounds would proceed as follows.
|Candidate||Round 1||Round 2|
This RCV result would remain the same regardless of whether some Independent voters ranked A or B as a second choice, and would remain the same regardless of whether a second candidate from faction A or faction B joined the race. This is a stable situation which leads to a majority-preferred candidate regardless of whether voters try to vote strategically.