Leading Election Systems – Pros and Cons

Our current voting system is fatally flawed and we can do better. That much we can  all agree on. So what’s the best alternative? Here we present the pros and cons of four options in detail. They are not necessarily the best four options, but they are the voting systems being compared in Oregon right now. Advocates are actively pursuing Ranked Choice (RCV) and Star Voting (SRV). Thanks for taking the time to get educated!

VSE Main 4 Labled

-Instant Runoff Voting (IRV) aka Ranked Choice Voting (RCV) Candidates are ranked on the ballot in order of 1st, 2nd, 3rd and sometimes 4th or more choices. It’s fine to leave candidates blank if you don’t have an opinion. 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. Some voters will have all of their rankings counted and others will only have some of their rankings taken into account.

Pros:

  • Simple ballot for voters to fill out, just rank as many candidates as you like in order.
  • Much more expressive ballot then Plurality.
  • Voters who prefer the front runners or candidates who don’t have a chance at winning can be honest. If there are only 2 candidates who have a real shot at winning all voters can be honest.
  • Is a form of Ranked Choice Voting, a type of voting system that is used around the world.
  • Some voting machines are already coded to count the votes.

Cons:

  • It’s not necessarily safe to vote for your favorite, there are cases where voting for your first choice is a bad strategy that can backfire and actually help elect your least favorite in elections where there are more then two strong candidates. (Fails Favorite Betrayal) **
  • If there are three or more viable candidates and your favorite is an underdog you might want to rank your preferred front runner 1st and your favorite 2nd.
  • Doesn’t take all rankings from all ballots into account and so is not the most accurate way of counting ranked ballots. If your first choice candidate is eliminated in later rounds your second, third, or fourth choices may never be counted. (Ranked Pairs and Borda Count are much more accurate ways to count ranked ballots.)
  • Is vulnerable to the spoiler effect aka. vote splitting, where adding an extra candidate can cause the candidate with the most support to lose.
  • Favors voters who prefer very strong or very weak candidates but puts moderately strong candidates and their voters at a disadvantage. This allows 3rd party voters to vote honestly if they are sure to lose but gives 3rd parties a glass ceiling if the Democrat and Republican parties are seen as the top 2.
  • Voters have to figure out which order to put all the candidates in before they can rank them since you can’t give tied rankings. This can be tricky if you aren’t sure which you prefer.
  • Hard for elections officials to process and understand the results, not a transparent process. Because you some 2nd and 3rd choice votes are worth the same as a 1st choice vote, while others are worth nothing there’s no way to compare how many votes each candidate got at the end without re-running the whole election using another ranked choice algorithm.
  • Votes must all be processed in one central location and can’t be tabulated by precinct. This makes it more vulnerable to top down election fraud and is a major logistical challenge.
  • If there is a non-representative result voters may never know about it due to to complexity of results. It would be up to elections officials and data analysis’s to crunch numbers and publish the data.
  • Recent work by Robert Norman, (2.) a mathematician at Dartmouth, suggests that IRV’s …[counting algorithm] 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. The 2009 Mayoral IRV election in Burlington, Vermont was one such sideways election, and the results led to the repeal of IRV in Burlington the next year.”
  • Has been tried and later repealed in a number of cities around the country
  • Puts viable 3rd parties at a strong disadvantage because that is the scenario most likely to trigger the spoiler effect or to encourage favorite betrayal strategy.

-Star Voting (aka. Score Runoff Voting or SRV): This is a hybrid of Score and Instant Runoff Voting which uses scoring in the first round and then implied rankings in the runoff. Voters give each candidate a score from 0-5. The two highest scoring candidates are finalists. The finalist that was preferred by more voters wins. Your ballot already shows which finalist you preferred. It’s fine to leave candidates blank if you don’t know about them or to give multiple candidates tied scores.

Pros:

  • Uses the most expressive type of ballot. Much more so than Plurality and more so than IRV. More information on the ballots allows for more accuracy.
  • Honesty is the best policy. Voters should vote their conscience.
  • Does not favor any type of voter or candidate. Equal weighing of votes.
  • In effect fixes the Favorite Betrayal problem from IRV and also the Strategic Voting problems from Score Voting. Using scoring in the first round and then implied ranking in the instant runoff makes Star Voting more accurate than either scoring or ranking alone.
  • Star Voting (SRV) is the most accurate voting system according to Voter Satisfaction Efficiency. It also does a good job of electing the Condorcet winner if one exists and offers compelling reasons why another winner was preferred by the electorate if VSE and Condorcet disagree on the best winner.
  • “[Star Voting (SRV)] has a Voter Satisfaction Efficiency of 91% all the way up to 98%… SRV is undeniably a top-shelf election method, and arguably the best out of all the ones I tested.” -Jameson Quinn, Harvard Statistics.
  • Because Star Voting (SRV) encourages voters to show preferences between all candidates it encourages positive, issue oriented campaigning as candidates try and get some support from their competitors constituents.
  • Passes Favorite Betrayal Criteria in practice. A voter should give their favorite a max score.
  • Allows voters to give the same score to candidates if they don’t prefer one over the other. This means that a voter can rate each candidate one by one and doesn’t have to figure out all the ratings before they can vote like is required with Ranked Choice Voting. This decreases voter burden.
  • It’s fairly simple to count and understand results. Results show total scores for each candidate and also the percentage of voters that preferred the winner over the other finalist.

Cons:

  • Voters have no incentive to be dishonest but some thought is required when deciding what scores to give candidates that aren’t your favorite or least favorite. This kind of honest strategic thinking does not hurt the overall results.
  • Strategic voting is possible but in the very unlikely case that a voter would benefit from tactical minimization or maximization strategy, there is no way to know which strategy would be best. In order to benefit from strategic voting a voter would need impossibly accurate polling data and
  • Hasn’t been used in a government election yet. This is a new voting system.
  • Some people are concerned that Star Voting doesn’t always pass the controversial “Later-no-harm” Criteria, but this is actually a good thing. Later-No-Harm states that a voter should never hurt their favorite by showing support for others, but this is at direct odds with overall representative outcomes. If there is a good compromise candidate that would make voters happier overall it is good for a system to encourage voters to show that support. In practice Star Voting does a good job at L-N-H because the odds are that showing nuanced support is more likely to help you than to hurt your favorite.
  • Ideally voters should have an informed opinion on all candidates that they prefer to their least favorite.

-Approval Voting: Check a box for as many candidates as you approve. The candidate with the most approval votes wins.

Pros:

  • Simple and doable using existing ballots and infrastructure.
  • Better results than Plurality Voting.

Cons:

  • Always favors the candidates that are perceived as most electable. This basically lets the media decide who can win, like in Plurality.
  • Doesn’t let you chose your favorite over a lesser-evil candidate so it doesn’t pass the test for honest voting.
  • Favors centrist candidates and strongly discourages 3rd party candidates.
  • Strategic Voting required for best results.
  • Doesn’t allow voters to express how they actually feel about the candidates.
  • Because voters must be strategic and dishonest there is no way to know how well the results matched the actual will of the people.

-Score Voting: Voters give each candidate a score, the candidate with the highest total wins. It’s fine to leave candidates blank if you don’t know about them.

Pros:

  • Simple to understand and explain.
  • Allows voters to express detailed opinions of each candidate.
  • Simple to implement and use for elections officials and easy to understand the results.
  • Not vulnerable to favorite betrayal strategy where voters feel they have to vote for a lesser evil candidate. It’s always best to give your favorite a max score.
  • Gets a very high rating in Voter Satisfaction Efficiency, or average voter satisfaction, and even if voters are tactical, results are still better than tactical IRV. At the worst Score Voting is as accurate as Approval Voting, which is still a pretty good system.
  • Uses the most expressive kind of ballot which lets us accurately gauge how representative the results are.

Cons:

  • Could hypothetically be vulnerable to strategic voting tactics. Voters from the dominant parties could “bullet vote” and get an advantage by giving their favorite a max score and everyone else a zero, even if they really do have a more nuanced opinion.
  • Voters from minor parties might want to do “approval” style voting where they give their favorite a max score and also give their preferred front-runner a max score as well with zeros for all others, even if they really do have a more nuanced opinion.
  • Score Voting produces the best, most representative results if everyone shows their honest, nuanced opinion, but people can gain an individual advantage with tactical voting.

Sources:

1. Favorite Betrayal in Plurality and Instant Runoff Voting: https://www.youtube.com/watch?v=JtKAScORevQ

2. 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

3. The Center for Election Science” https://electology.org/

and their VSE page: http://electology.github.io/vse-sim/VSEbasic/

4. Equal Vote, www.equal.vote

5. Range Voting Wikipedia: https://en.wikipedia.org/wiki/Range_voting

6. RCV OR on Loomio: https://www.loomio.org/g/mlgtGHuy/rcv-oregon

** It has come to our attention that while FairVote has a lot of great info they have repeatedly made some false claims. Detailed fact checking of their info has been made on a few Loomio threads for RCV Oregon. Any info quoted or gleaned from them in the future will need to be fact checked.

 

**The above graph above shows the Voter Satisfaction Efficiency (VSE) of many voting systems side by side. VSE is a measure of accuracy in voting systems that tells us how many voters are as happy as possible with the outcome of the election. It is determined using simulated elections with a wide variety of circumstances and variables. A score of 1.0 VSE means that as many voters as possible are as happy as possible with the elections outcome.

The different colored bubbles show how different strategies effect an elections accuracy. Systems with the blue bubble at the right of their cluster do best when most voters are honest. Systems with a red bubble to the right, like our current system, Plurality, are most accurate when most voters are dishonest. Honest Voting is a key part of accuracy because if voters don’t vote honestly there is no way to know if a real life’s election was a success or not. We believe that VSE is the best way to determine accuracy using modern election science and that Condorcet is also a very useful metric, particularly for judging elections that didn’t use the most expressive ballots possible.

VSE graph and election simulations are from Jameson Quinn. Statistics Ph.D. candidate at Harvard University working on voting systems and Director of The Center For Election Science. Bio: https://electology.org/who-we-are 

Source: http://electology.github.io/vse-sim/VSEbasic/

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One thought on “Leading Election Systems – Pros and Cons

  1. Pingback: Star Voting: The Quest for Democracy | Dreamtime Compass

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