Comparing RCV and STAR Voting

Traditional Ranked Choice or Version 2.0?

Traditional Instant Runoff Voting (IRV) is the Ranked Choice O.G. - it's been used around the world and the states for more than a century. STAR Voting (Score Then Automatic Runoff) is a modern preference voting method that was invented to go further to deliver on the original goals, while addressing known issues with the old method.

Ranked Choice Voting and STAR have a lot in common:  Only one election is needed, primaries are optional in most cases, voters have more voice. Both are user friendly. Both can be used for single winner, multi-winner, or proportional representation elections ...

… That said, there are significant differences. 

Technically "Ranked Choice Voting" or RCV is an umbrella term for any number of ranked ballot voting methods, however in practice RCV is Instant Runoff Voting, the method discussed below.

 

Metrics For Comparison:

The Equal Vote Coalition evaluates voting methods according to five primary metrics: equality, honesty, accuracy, simplicity, and expressiveness

 

Equality: 'One Person, One Vote'

The U.S. Supreme Court has found unequivocally that 'One Person, One Vote' requires that "each vote be given as much weight as any other vote." Put simply, our very notion of democracy requires that the voters and the candidates are on an even playing field in every election, and every proposed reform should be scrutinized through this lens.

  • STAR Voting provides equality to voters. 

In STAR Voting voters are able to weigh in on as many candidates as they want, at any level they want, and all that data is counted. This is the key to passing the test of balance and the Equality Criterion. Moreover, not matter who the finalists end up being, the STAR Voting runoff ensures that your full vote goes to the finalist you prefer. The runoff is the key to ensuring that a voting system gives you an equally weighted vote, whether your favorite can win or not. With STAR Voting, every possible vote in both the scoring and automatic runoff stages has an equal, and opposite vote that could be cast. In order for a voting method to not split the vote, it needs to pass the test of balance. 

  • RCV fails 'One Person, One Vote.' 

Ranked Choice Voting, (also known as Instant Runoff Voting,) by its very design, gives some voters more than one bite at the apple while giving others just one. In RCV, second choice votes only ever count for those voters who happen to see their first choice eliminated before their second choice. Whether you pick a strong consensus candidate or a weak extremist second, if your first choice hangs around in the count longer, your second choice is never considered by IRV. The 2009 Mayoral IRV election in Burlington, Vermont is a real-world example of how IRV's failure to provide an equal vote can result in an obviously non-representative outcome and subsequent repeal of the system.

 

Does the voting method eliminate vote splitting and spoilers? 

Vote-splitting is one way that voting methods can leave voters divided and conquered, even when they had a majority.
  • RCV: In voting methods like Choose-One Plurality and in Ranked Choice Voting, coalitions of voters who have more candidates on their side have a mathematically less powerful vote than voters who only support one candidate. RCV mitigates it, but vote-splitting can still happen in any round.  
  • STAR: Voting methods like STAR Voting, Score Voting, and Approval Voting allow voters to show support for multiple candidates and show that they prefer all the candidates they support over those they do not. This eliminates vote-splitting and spoilers caused by the voting method itself. 

Honesty:

Can voters safely express their honest opinion on the ballot? Do voters need to vote strategically in order to not waste their vote?


Voters in RCV can't always safely vote 1st choice for their honest favorites

Ranked Choice proponents often make the inaccurate claim that “With RCV, voters can honestly rank candidates in order of choice. Voters know that if their first choice doesn’t win, their vote automatically counts for their next choice instead. This frees voters from worrying about how others will vote and which candidates are more or less likely to win.”

In fact, you can only safely rank candidates honestly in RCV if your favorite either has no chance at all or is a very strong candidate. There is no guarantee that if your favorite is eliminated your next choice will actually be counted. This video and this video show clearly how RCV suffers from a type of vote-splitting called the center-squeeze spoiler effect:

 

 

Because RCV doesn't eliminate the spoiler effect, major parties can honestly propagandize against supporting up-and-coming third party candidates, as they do in Australia, which has used RCV at the national lever for over 100 years: "This confusion is often encouraged by the major parties who do not want people to give a first preference to a minor party. In left-wing inner-city seats around Sydney and Melbourne, where the Greens are now challenging the hold of the Labor Party, Labor campaigners often will claim that a vote for the Greens would help the Liberal Party, sowing confusion about our electoral system, in order to bring progressive voters back to Labor."

 

Score Voting ensures that it's always safe to vote for your favorite, but has some other strategic issues 

Score Voting is a predecessor to STAR Voting. In Score Voting, candidates are given scores and the highest scoring candidate wins. While very simple, RCV advocates argue that rating systems like Score Voting are vulnerable to 'bullet voting' - that is, they claim that voters should support just one candidate on the ballot in order to maximize the chance of one's favorite winning. This can be easily refuted.

For example, let's take a classic "spoiler" scenario where there is a strong opposition candidate with say 45% of the vote, and then a majority faction which is split between a major party candidate who is likely to win, and a 3rd party candidate who is well liked, but likely to lose. 3rd party voters in this election should always give their favorite a max score, but they also have a strong incentive to show that they strongly prefer the major party candidate over the opposition. Similarly, the major party voter should give their favorite a max score, but they also can safely show that they support the 3rd party candidate.

If we look at a scenario where the election is closer and the major party and 3rd party voters are less confident about who the frontrunner is, the incentives to score both candidates gets even stronger. Voters priority in a given election is to ensure that they get the best representation possible whether or not their favorite can win. In Score Voting, voters are incentivized to show their support for all the candidates on their side, and because voters can give their full support to as many candidates as they want, they'll be able to prevent vote-splitting and avoid a spoiled election by doing so. 

Attacks centered around Bullet Voting are particularly disingenuous because they set up strategic voting as a moving goal post. In the current Choose-One Plurality system strategic voting occurs any time a voter does not vote for their favorite in order to hopefully get a better outcome. In Score Voting that is NEVER incentivized, though it is a necessary strategy in some cases for RCV voters, as we'll explain further below.

While it's true that some voters may bullet vote in Score Voting, as they may do in any system, it's also worth noting that voters can and do bullet vote in RCV, and that the reasons for this have very little to do with the reasons often cited. FairVote, the largest and most well funded organization advocating for RCV has a long history of disingenuous attacks other alternative voting methods which they see as competing with their proposal, and they have agued that bullet voting is a deal breaker in Score voting and Approval Voting) for decades in 1000s of presentations, articles, posts, and statements, but their own data shows that on average 32% of RCV voters bullet vote. A recent article from their research department analyzing real world RCV election data does a great job of explaining why bullet voting is actually not as problematic as one might expect, namely because it turns out that voters are most likely to bullet vote if voting more expressively wouldn't make a difference anyways, such as when voters who know that their favorites are almost sure to win a landslide victory. This matches the trends reported in election data from other voting methods. The FairVote article goes on to show that the elections most likely to exhibit high rates of bullet voting are those where voters are instructed to do so explicitly by candidates or by sources they trust. The message here is clear, voting reform advocates sounding the bullet voting alarm are likely creating the problem they profess to be concerned about. 

As we've shown here, the worst attacks on Score Voting regarding strategic voting are false, unfounded, and harmful in their own right. That said there are some valid concerns regarding tactical voting and Score Voting that can be addressed. In Score voting, voters who want to ensure that their candidates beat the opposition do have an incentive to exaggerate their scores.

Voters in the scenario above may want to give both the candidates on their side a max score to ensure that they defeat the opposition, even though they do have a preference. This is why in STAR Voting, the two highest scoring candidates are finalists who advance to an automatic runoff. In the STAR Voting runoff, every voter's ballot is counted as one full vote, just like it would be in a top two general election. The addition of the STAR Voting runoff empowers voters to score candidates more honestly, because as long as they show their preferences their full vote will go to the finalist they prefer. STAR Voting renders tactical voting and vote exaggeration unnecessary.  

 

STAR Voting combines the best aspects of both, while addressing valid concerns with the older proposals

With STAR Voting, you can honestly support your true favorite(s) and you can support your other candidates at the level you want while ensuring that your vote will be powerful as possible. Voters don't have to worry about wasting their vote, and don't have worrying about what other voters are going to do. The STAR Voting scoring round allows voters to show their preference order between the candidates as well as showing their honest level of support for each.

It all comes down to voter intent. Voter intent should not be corrupted by the system. The system should count your vote and it should be able to make a difference if possible and help you gain representation, but in Ranked Choice Voting that's not necessarily the case. This can often be traced back to the fact that the RCV algorithm doesn't count most of the rankings voters put down on their ballots. Which of your rankings will be counted and which will not depends on the order of elimination. As a result, it may not be safe to vote for your favorite in RCV, just like with traditional Choose-One Voting. Worse, in some cases, voting your conscience can actually backfire, resulting in a worse outcome than if you hadn't voted at all in RCV. 

Voters in any system can chose to vote in a way that's not as effective as it could have been, but the STAR Voting system won't waste the vote of a voter who showed up and voted their conscience and your vote will never backfire. It's also next to impossible for an inexperienced voter to accidentally waste their vote in STAR Voting. 

There are a number of different ways a vote can be wasted. Let's break it down:
  1. Wasted Vote: Spoiled Ballots. A voided ballot which is thrown out due to voter error. Spoiled ballots are much more common in RCV than in traditional Choose-One Voting and are highest for lower-income voters and historically marginalized communities. In RCV, equal rankings, skipped rankings, and double rankings are all examples of ballots errors. In STAR Voting, equal scores and skipped scores are allowed, and with protocols in place to cover the scenario where a voter fills in too many bubbles, it becomes almost impossible to accidentally void your ballot.



  2. Wasted Vote: Lazy voting. A vote that can’t transfer or doesn't make a difference in the runoff because the voter wasn’t as expressive as they should have been and didn’t show preference order between the finalists when they actually did have a preference. This voter behavior can happen in RCV or STAR, but it's only problematic if the voter actually had a more nuanced opinion. It's impossible to tell if a bullet voter was being intentional or lazy from looking at the ballot alone and it's worth noting that a bullet vote is not necessarily a strategic vote, though the word is often used that way. 

    According to FairVote as of 2021 'bullet voting' rates in RCV average 32% and vary widely based on the election circumstances with more polarized voters being the most likely to bullet vote. In STAR Voting, election data available to date shows much lower rates of bullet voting but similar trends as to who bullet votes and why. 



  3. Wasted Vote: Ballot Limitations. A vote that couldn’t transfer because the voter wasn’t allowed to rank enough candidates in RCV. Most RCV elections limit voters to only ranking a certain number of candidates. In NYC it's 5. (3, 4, 5, or 10 are common.) A voter who doesn't like the finalists may not be able to rank the finalists at all unless they strategically rank them higher than they deserve. In STAR Voting, voters are always allowed to rate as many candidates as they want to support.


  4. Wasted Votes: False Majority. In RCV, tabulation stops when a candidate is the top choice on a majority of remaining ballots, even if there was another candidate who was actually preferred on even more ballots. In RCV only a fraction of the rankings voters put down are actually counted, and it's possible that if the rest of the ballot data was considered that another candidate had an even larger majority.

    In STAR Voting all ballot data is counted. In the scoring round all scores are totaled, and in the runoff every ballot counts as one vote. In STAR Voting the winner is the finalist who was preferred by a majority of voters who had a preference between those two. 



  5. Wasted Votes: Order of elimination and incomplete tabulation. In RCV, a voter's other candidates may be eliminated before their first choice, so that by the time their favorite is eliminated the vote may have nowhere to transfer to. This is called an exhausted ballot and these ballots are not counted in the deciding round of the election. On average in competitive RCV elections over 10% of ballots are exhausted. In some cases, the eliminated candidate may have actually been the candidate preferred over all others, but because RCV doesn't count most of the rankings voters put down, it can fail to elect the most popular candidate.

    Compare these uncounted exhausted ballots in RCV to a vote of no-preference in STAR Voting, where a voter explicitly chose to score both finalists equally. These votes are counted and do make a difference to help advance the candidates who were more preferred. Allowing voters to give equal scores in STAR is the key to preventing spoiled ballots, and it's also key for eliminating vote-splitting between similar candidates and maintaining election accuracy in larger fields of candidates.  

NOTE: For simplicity's sake, we are referring to single-winner elections above, but the same trends in STAR Voting and Ranked Choice Voting hold if we were to talk about Proportional STAR Voting and Single Transferable Vote, the proportional versions of both methods.

NOTE: In this article we are using the common meaning of a "wasted vote" for voters, "Don't waste your vote! Vote for So-And-So." In this sense a vote is wasted if it's unable to make a difference when it otherwise could have, or if the system itself is not counting a vote. Whether or not wasted votes are numerous enough to throw an election and change the winner, wasted votes leave voters feeling powerless, disenfranchised, and they are a leading reason many people cite for not voting at all. In the USA almost 50% of voters don't vote.

The term wasted vote is also used in another sense in discussions about gerrymandering or proportional representation. In that sense, in a given election the term "wasted votes" refers to the number of voters who did not vote for the winner and who may be left feeling unrepresented, even if their vote was counted and did make as much of a difference as it could have. 


Accuracy:

How accurately does the voting system reflect the will of the people?

Voter Satisfaction Efficiency models representation accuracy

Voting method simulation is used primarily to determine how accurately a voting method will produce an outcome that represents the will of the electorate. In a real human election it's hard to actually know what the voters really wanted - they could have been voting strategically, exit polling is imprecise and so on. By running simulated voters through thousands or millions of simulated elections, voting systems can be concretely evaluated and compared.


 

STAR Voting tops the list

STAR Voting simulates best-in-class in the several election method simulators that have included it. Across the board, with both honest voters and mixtures of strategic voters, STAR is "unquestionably a top-shelf method."

IRV offers middle-of-the-road representation accuracy

Traditional IRV, by contrast, doesn't come close to the top of the list. Recent work by Robert Norman, a mathematician at Dartmouth, suggests that IRV's topsy-turvy math issues would create non-representative outcomes in one in five close contests among three candidates and that with larger numbers of candidates, it would happen even more often.

Burlington demonstrates IRV's counting failure with crystal clarity: Three strong candidates faced off - we'll call them A, B and C. A majority of voters expressed a preference for A over B, and a plurality of voters expressed a preference for A over C, yet the IRV count eliminated A before either B or C, and elected a candidate not supported by the majority. Not surprisingly, Burlington repealed IRV the next year.



Simplicity:

How easy is the system for voters to understand and cast ballots, and how easy is it for elections officials to tabulate and hand-recount?

 

The Ballots

For a small number of candidate choices, it's arguable whether scoring or rank ordering is simpler: if you only want to support one, bubbling in "first choice" or "top score" are essentially equivalent.

As the number of candidates and choices increase, however, scoring clearly becomes by the simpler method, because each candidate can be considered individually, where ranking systems essentially require the voter to sort the candidates before filling out the ballot. As a Wikimedia board member stated:

"I actually voted in an election conducted under a Condorcet method (specifically Schulze's beatpath method): the Wikimedia board election. There were more than a dozen candidates, and about the only way I could vote intelligently was to first rate them, then turn that into a ranked ballot. So obviously a rating-type ballot (where the second step was not needed) would be easier and quicker to cast."

Multi-round elimination is complex

The mechanism for tabulating RCV can remain opaque even for sophisticated voters. Steve Pond wrote the following about RCV after its adoption as the voting system for choosing Best Picture by the Motion Picture Academy: "A year and a half after the Academy went to a different system for counting Best Picture ballots, nominees and voters and campaigners still don't understand how it works. And it's driving me crazy."

Because RCV's counting algorithm goes through one round for each losing candidate until a winner is decided, elections can take many rounds to compute. The image below represents a sample election vote tally in the multi-round RCV process. It's hard for observers and lay voters to draw meaningful conclusions about voter preferences from these intermediate results:

 

STAR Voting always completes in two rounds

STAR Voting is simple to tabulate, with transparent results that show overall popular support for every candidate. You can see the election results of the sample election run with STAR below:

RCV requires centralized counting

The winner of an RCV election cannot be tabulated until all ballot information is reported to a central location. Maine, which adopted RCV for some elections in 2018, is dealing with the headaches of this system. "Ballots would have to be shipped by town clerks to a central location in Augusta for additional voting rounds. Thus the outcome of an election in a multiple-candidate race might not be known for several weeks."

We think it's likely that modern elections offices would use the internet to transfer election data from the counties to the state HQ, so we expect it wouldn't take weeks, but regardless, the lack of precinct summability is a real weakness of RCV. Each locale has to come up with all of the many possible combinations of rank orderings and report the total for each, in order that the central counting authority can begin the process to determine the winner. These partial results give little meaningful information to the voters. A small subset of one election's partial results in RCV might look like this:

svi_irv_presum.png

 

STAR Voting results can be summed by precinct

STAR Voting gives information that is useful in understanding how the local electorate felt about the election and makes the results easier to verify by hand-recount. Each precinct sums the scores for each candidate and creates a preference matrix tallying how many ballots prefer each candidate to each other candidate in the race. The central election authority adds up all the precinct sums and all of the precinct preference matrices. The final winner is determined by looking up the two top scoring candidates in the final preference matrix to see which one more voters preferred.

Reading the preference matrix: each element in the matrix represents the voter preferences of one candidate over another. So the highlighted number "15" in the second column of the first row means that 15 voters gave A ("A>" row label) a higher score than B (column label). The highlighted 10 in the first column of the second row means that 10 voters gave B a higher score than A. The head-to-head total is A:15 to B:10.


Expressiveness: Can the voter express a nuanced opinion on the outcome?


Ranking is more expressive than plurality

Our current voting system, where we are limited to picking a single favorite in each election, is the least expressive voting system humans have ever constructed. Ranked Choice Voting allows the voter to express an opinion on multiple candidates by placing them in preference order.

Preference order alone leaves out information

The same ordering A > B > C could mean that the voter thinks any of the following:

  • A is an awesome candidate, B is mediocre and C is the devil incarnate
  • A is awesome, B is almost as awesome, and C is just a hair less awesome than A and B
  • A is above average, B is mediocre, and C is mediocre and dishonest

Furthermore while RCV lets you express support for more than one candidate, it doesn't actually count that secondary support at all until your first choice candidate is eliminated and even then it's not guaranteed. For some voters your first choice can be eliminated and your next choices will not be counted. This is known as an "exhausted ballot", meaning that these ballots are not counted in the final round which determines the winner. The more viable candidates are in the race the more likely this is to happen, and the phenomena predictably puts voters who prefer a strong underdog at a disadvantage.

Scoring is more expressive than ranking

Instead of only counting the voter's support for one candidate at a time, STAR allows the voter to express, and counts, a nuanced level of support for any number of candidates on the ballot.

It's Time For 2.0

The need for true election reform is more apparent now than ever before, and the recent adoption of RCV in Benton County, OR and the state of Maine show that electorates on both coasts are ready for more expressive voting systems. What we need now is the upgraded version, that actually gets rid of the spoiler effect, once and for all, and isn't vulnerable to repeal after adoption due to complexity of implementation and non-representative outcomes.

The American electorate is hungry for a real solution to our broken political system. We clearly need an election system that gives us all an equal say, accurately reflects our collective will in the outcome, is simple for us to ballot and for election officials to tabulate, and that allows us to expressively share our honest opinions on the outcome. By all these measures, the new Ranked Choice - STAR Voting - is the clear winner.

 

Sources:

1.) Instant Runoff Voting (IRV) suffers from a defect known as nonmonotonicity, wherein increasing support for a candidate .. may adversely affect that candidate’s election outcome... Results suggest a lower bound estimate of 15% [monotonicity failures] for competitive elections). In light of these results, those seeking to implement a fairer multi-candidate election system should be wary of adopting IRV.” Frequency of monotonicity failure under Instant Runoff Voting: Estimates based on a spatial model of elections. By Joseph T Ornstein, University of Michigan, Dept. of Political Science and Robert Z. Norman, Dartmouth College, Dept. of Mathematics, 2013. 

2.) "The rate of ballot exhaustion was high in each election, ranging 9.6%–27.1%." Ballot (and voter) “exhaustion” under Instant Runoff Voting: An examination of four ranked-choice elections. By Craig M. Burnett, University of North Carolina, and Vladimir Kogan, Ohio State University, USA. 2015.

3.) "When we examined the 96 ranked-choice voting races in our sample from across the nation, our analysis found an average of 10.92 percent of ballots cast are exhausted by the final round of tabulation. (pg. 10)" and "the eventual winner failed to receive a true majority 61% of the time." The Maine Heritage Policy Center "A False Majority:  The Failed Experiment of Ranked-Choice Voting," By Gagnon, Crepeau, Sigaud. August 2019.

4.) "We find that RCV helps reduce the substantial drop in voter participation that commonly occurs between primary and runoff elections. Otherwise RCV does not appear to have a strong impact on voter turnout and ballot completion. In a case study of Minneapolis we find similar levels of socioeconomic and racial disparities in voter participation in plurality and RCV elections." Voter Participation with Ranked Choice Voting in the United States. By David C. Kimball and Joseph Anthony, Department of Political Science University of Missouri‐St. Louis St. Louis, MO. 2016.

5.) "Drawing on previous research conducted by the Maine Policy Institute, McCarty examined 98 RCV elections from 2006 to 2019 and found that, on average, 10.8 percent of ballots casted were considered exhausted by the final round." Expert Report Reveals Weaknesses of RCV. By Isabelle Christie. 2020

6.) "Concerns about the fairness of IRV led at least four jurisdictions to repeal... Burlington, VT (2006–2009), Cary, NC (2007–2009), Pierce County, WA (2006–2009), Aspen, CO (2009)." and "Consistently, precincts where more African-Americans reside are more likely to collect overvoted, voided ballots. And this often occurs where more Latino, elderly, foreign-born, and less wealthy folks live." Overvoting and the Equality of Voice under Instant-Runoff Voting in San Francisco, California Journal of Politics and Policy. By Francis Neely and Jason A. McDaniel San Francisco State University. 

7.) Voter Satisfaction Efficiency (VSE) studies by Dr Jameson Quinn Phd. At the time this study was released Quinn was Vice Chair for the Center for Election Science. Quinn is now on the board of the Equal Vote Coalition http://electionscience.github.io/vse-sim/vse.html

8.) Election Accuracy. A comprehensive list and overview of studies, sources, and citations comparing voting methods including RCV and STAR. http://starvoting.us/accuracy