Comparing Voting Methods: A Report Card
Choose One Plurality, Ranked Choice, and STAR Voting
THE OPTIONS: 3 VOTING METHODS UNDER CONSIDERATION
Our Current 'Choose One' Voting Method, formally known as Plurality or First Past The Post, is used in the vast majority of the USA and many places around the world. Each person votes for one candidate only. The candidate with the most votes wins. (Factors like the electoral college complicate the process but you get the idea.)
STAR Voting is a modern voting method where voters use a 5 star ballot, giving candidates a score from 0-5 to show their preferences. Candidates left blank receive a zero. Voters can give the same score to multiple candidates if they have no preference between them. The two highest scoring candidates are finalists. The finalist preferred by more voters wins.
Ranked Choice Voting (RCV): Invented 150 years ago, Instant Runoff Voting is the most commonly used method for counting Ranked Choice (RCV) style ballots*. Voters rank candidates on the ballot in order of preference: 1st, 2nd, 3rd, 4th, or more depending on logistical factors. If a candidate has a majority of first choice votes, that candidate wins. Otherwise, the candidate with the fewest first choice votes is eliminated. If your first choice is eliminated, your vote goes to your next choice- if they haven’t been eliminated yet- and the process repeats in rounds until one candidate has a majority of the remaining ballots.
*Note that Ranked Choice Voting is technically an umbrella term which includes the Condorcet methods, Borda Count, Bucklin Voting, and others. In recent years Instant Runoff Voting (IRV) was rebranded and is now widely know as Ranked Choice Voting. For clarity we will use RCV as it's commonly used in the USA to refer to Instant Runoff specifically. Instant Runoff Voting is also known as Alternative Voting, Preference Voting, and by a number of other names around the world.
HONESTY - Encourages and rewards honest voting:
'Choose One': Only voters who prefer one of the two front-runners should vote honestly. Since barely half of voters in the US are registered with a major party this is a fail. (1.) Many voters have to vote strategically or vote for the 'lesser of two evils' to ensure that their vote is not wasted and to prevent vote splitting and the Spoiler Effect from electing the least preferred candidate. GRADE: F
STAR Voting: With STAR Voting voters can and should vote honestly and vote their conscience. Strategic voting is not incentivized and is as likely to backfire as it is to help a voter. GRADE: A
RCV: Most voters tend to vote honestly, but for those who prefer a strong underdog ranking your favorite in first place can backfire, causing your second choice to be eliminated prematurely and allowing your least favorite to win. If your favorite is pretty strong but you think they may not make it into the top two with first choice votes alone, you are better off marking a front-runner as your first choice. You can always vote your conscience if there are only 2 viable candidates but the more viable candidates there are, the more you should consider voting strategically.
RCV advocates often say that with RCV you won't need to vote lesser evil, but that claim does not pass a fact check and a few well known organizations who advocate for RCV are notorious for selling the reform with overblown or completely false claims on a regular basis. GRADE: B
EQUALITY – Fair, equal, and impartial. Doesn't give anyone an unfair advantage.
'Choose One': Two similar candidates can split supporters between them and both lose, even if one or both had support from a majority. Because of vote splitting any voter who likes more than one candidate is at a huge disadvantage as is any candidate who is similar to their opponent. Furthermore, closed partisan primaries further disadvantage 3rd parties and candidates who are not incumbents or deemed “electable”. GRADE: D
STAR Voting: STAR Voting eliminates vote splitting by allowing voters to support multiple candidates, and then counting all that ballot data at once. This gives each voter a mathematically equally weighted vote. Any way I fill out my ballot you can fill yours out in an equal and opposite fashion so that our votes cancel each other out. This is one of the few systems that doesn’t give some voters or candidates an unfair advantage. GRADE: A+
RCV: The ranked ballot is somewhat more fair than our current system because it mitigates vote splitting but in RCV not all those rankings are actually counted. Advocates say that in RCV if your first choice is eliminated, your next choice will be counted, but for many voters this isn't true. It depends on the order that your candidates are eliminated in. By the time your first choice is eliminated your 2nd and 3rd choices may already be gone. This means that some voters get more say than others. Not fair and not equal. GRADE: C
ACCURACY – The candidate that best represents the will of the electorate should win. For the purposes of this article a number of metrics were used to assess relative accuracy. Voter Satisfaction Efficiency, Condorcet Winner, Ka-Ping Yee, and Bayesian Regret tend to agree on relative election accuracy trends.
'Choose One' Plurality is the least accurate voting system out there. It only gives accurate results if there are 2 candidates in the race and even then it's likely that those candidates don't represent everyone. Elections often fail to elect the candidate with the most support and there is a high danger of vote splitting, i.e. The Spoiler Effect. This drives dishonest voting, which is an even bigger threat to accurate results. GRADE: D
STAR Voting: STAR Voting gives the most accurate, representative results of any voting system tested when voters are honest. Even if voters are dishonest and strategic, Voter Satisfaction Efficiency (2.) simulations show that results are still significantly more accurate than the other methods described here. STAR Voting picks the candidate that best represents the will of the electorate. GRADE: A
RCV: RCV is about ½ way between our current system and STAR Voting in terms of accuracy. It gives accurate results for elections with only 2 viable candidates, but can fail to elect the candidate who was preferred over all others in up to 1 in 5 elections or worse when there are more candidates according to expert analysis. (3.) GRADE: C
SIMPLICITY - Simple to fill out the ballot. Simple to understand how votes are counted. Simple for elections officials.
'Choose One': This ballot is about as simple as it gets, but the need for strategic voting can make it hard to decide who to vote for, even if you know who you like. Tallying votes is simple to understand and and simple for elections officials. GRADE: A
STAR Voting: 5 star ratings are very familiar and are user friendly. Voters only need to vote once and primaries are not necessary to get accurate election results.
Ballots are counted in different ways for the two rounds. The first round looks at scores and the second round looks at the preferences. This can be confusing at first. The two round tabulation process is simpler than systems like IRV that have multiple elimination rounds.
STAR Voting uses a simple enough algorithm that hand recounts can be done and basic addition is all that’s required. STAR is user friendly for elections officials because it’s precinct summable which means that ballots can be counted locally and don't need to be processed in a central location. GRADE: B
RCV: Ranking candidates is intuitive but "spoiled" ballots are still fairly common. If you accidentally give candidates the same rankings or make other errors your ballot is invalidated. Voters only need to vote once, and there’s usually no primary.
Understanding how candidates are eliminated can get quite complicated if you look at the details. The multiple tournament style runoff rounds require an algebraic algorithm to tabulate. If a voter's first choice is eliminated some voters will have their next choice counted, but others wont. Some ballots are exhausted and aren't counted in later rounds. It depends on the order that your candidates are eliminated in.
Ballots can't be processed locally and must be tabulated in a central location which can be a huge logistical challenge. Hand recounts are difficult, especially on larger scales. GRADE: C
EXPRESSIVENESS - Voters can express their full opinion
'Choose One': Because we can only vote for or support one candidate, this is the least expressive system possible. At least we get a vote. GRADE: D
STAR Voting: Voters give each candidate a score from 0 through 5 and can show how much they like each candidate as well as who they prefer to who. If they don’t have a preference voters can give the candidates the same scores. All the info you give on your ballot will be counted. GRADE: A
RCV: Voters can rank 3 or more candidates but you are unable to show ties or show how much you actually like each. Not all the rankings you give will be counted, depending on the elimination process. GRADE: B
VIABILITY - Has a good chance of being passed and not being repealed:
'Choose One': Plurality, aka First-Past-The-Post is the most used election system in the world but it is extremely unpopular! Many people are trying to repeal and replace it with something better and many have succeed. Now that we have technology to help count ballots there’s no reason to have an unrepresentative and archaic voting system. It should be illegal. GRADE: D
STAR Voting: STAR Voting is the new and improved hybrid of RCV and Score Voting. It hasn't been adopted for governmental elections yet, but analysis is very promising and all available evidence shows that it will outperform the voting systems in use currently. Most voting machines would need a software upgrade and the code and programing is simple and doable. Many state constitutions require a “win by plurality” which STAR offers. The fact that STAR Voting has perfectly equally weighted votes could make it the gold standard for one-person-one-vote. These two things make STAR Voting widely constitutionally viable. Precinct summability means that STAR Voting scales well and is a viable option for national elections. GRADE: B
RCV: RCV is used by countries like Australia and Ireland and in cities around the US. It was recently passed by Maine and also in Corvallis, OR, among others. RCV has a resurgence in momentum, but despite having been in use for over 100 years it has failed to catch on widely. RCV was recently repealed in Burlington, Vermont and in four other cities in recent decades (4.), in part because of it's problems with the spoiler effect, logistical challenges with the complex algorithm, and non-precinct summability.
Many who advocate for RCV do so believing that it goes significantly father than it does. Many people falsely believe and state that it is safe to vote your conscience, that if your favorite is eliminated your next choice will be counted, and that it solves the spoiler effect, even though these claims are demonstrably false. Others fear that passing a reform on false pretenses, only to repeal it when people realize the truth, could set the election reform movement back in the long run.
Additionally, RCV is unconstitutional in many places due to implications from the way the many elimination rounds are conducted, including in the state of Maine where it was recently adopted by ballot initiative but can not be used for statewide offices (5.) RCV also raises serious concerns around One-Person-One Vote. The fact that some ballots are exhausted and not counted in the final round, and the fact that that some voters who's first choice is eliminated will not have their next choice counted are both examples of where RCV fails to deliver each voter an equally weighted vote, as has been mandated "as nearly as is practicable" by the Supreme Court.
While RCV has played an important role in the evolution and adoption of voting reform, nearly all scientific evidence on voting theory points to the reality that it is not the reform of the future.
(1.) “29% of voters were registered Dem. and 26% Rep. at the beginning of the last election cycle with 42% Ind.” Democratic, Republican Identification Near Historical Lows. http://www.gallup.com/poll/188096/democratic-republican-identification-near-historical-lows.aspx
(2.) VSE-Sim. Voter Satisfaction Efficiency, or VSE, is a measure of the accuracy of a election method which uses thousands of simulated elections with honest and strategic voters who cluster on issues in a realistic way. http://electionscience.github.io/vse-sim/VSE/
(3.) “[IRV] can cause spoilers in up to 1 in 5 elections or worse when there are more candidates according to expert analysis.” 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 https://www.researchgate.net/publication/258164743_Frequency_of_monotonicity_failure_under_Instant_Runoff_Voting_Estimates_based_on_a_spatial_model_of_elections
(4.) “STV/IRV was used in roughly two dozen US cities in the early 1900’s and repealed in all of them except for Cambridge, MA. In the modern era it was repealed in Ann Arbor, MI in 1976, then these four places in the past decade: Burlington, Vermont. Cary, North Carolina. Pierce County, Washington. Aspen, Colorado.”- Clay Shentrup, co-founder of the Center For Election Science
This blog post was originally written by Sara Wolk as part of the Portland chapter of RCV-OR's analysis of voting systems.
Written February 2017. Edited 3/20/18.