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Scoring the Candidates

Continued from page 2

By Alan T. Sherman '87, Warren D. Smith '84, and Richard T. Carback III

September/October 2008

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Warren Smith performed computer simulations using ­Bayesian regret analysis to compare election methods, measuring the quality of election outcomes by summing the utility--or satisfaction--of the voters. These simulations indicate that switching from plu­rality voting to range voting would improve election outcomes as much as switching from dictatorship to democracy would. Range voting also outperforms all common alternative systems on average--no matter how many honest, strategic, and uninformed voters cast their votes, and no matter how many candidates run. (See William Poundstone's Gaming the Vote for a good summary of this analysis.)

Range voting using a 0 to 9 scale can be done on existing computerized or lever voting machines, punch cards, or paper ballots. Voters would simply select a score for each candidate. In fact, French researchers found that voters make fewer errors on range ballots than they do on plurality ballots.

Changing the way the U.S. president is chosen may seem daunting, but plurality voting is a shaky foundation on which to rest the fate of the country. It doesn't let voters express how strongly they feel, which is a big drawback when some choices are much worse than others. Plagued by the prospect of spoilers and illogical outcomes, it perpetuates a two-party duopoly, minimizing democratic choice.

IRV can't fix the problems of plurality voting. But computer simulations, Spartans, and trillions of generations of honeybees offer convincing evidence that range voting can.

Alan T. Sherman, PhD '87, teaches computer science and is part of the National Center for the Study of Elections at the University of Maryland, Baltimore County. Warren D. Smith '84 cofounded the Center for Range Voting ­(rangevoting.org). Richard T. Carback III is a PhD candidate at the University of Maryland, Baltimore County.

Comments

  • IRV Promotes More Sincere Voting
    What Mr. Smith, Mr. Sherman, and Mr. Carback III fail to not about the inherent flaw in Range voting is that it is seriously susceptible to insincere or tactical voting.  For instance, If i like Ralph Nader or Bob Barr as my choice for president, and I want my candidate to win, then in the Range Voting system, i can further their interests by rating every other candidate a 0 out of 9, or whatever the arbitrary top end number is determined to be in this entirely theoretical system.  So i would vote the following:  Nader 9, Barr 9, Obama 0, McCain 0, McKinney 9.  (These are not my personal preferences, just an example of the application of this system on REAL PEOPLE that is missing from all this mathematical theory.)

    The authors of this article seem to imagine people won't work to game the system and will vote entirely honestly.  On that account, they are mistaken.  If i can change my vote, as in the example above, to increase the likelihood that a candidate that matches my values will win, I and 99% of the other people in America will do so.  In gaming a range voting election as described, the outcome would hardly be different from plurality elections.

    Unlike Range Voting--and even worse Approval Voting--Instant Runoff Voting provides very insignificant incentives to rank candidates different than a voter's sincere preferences.  There are highly improbable (never happened thusfar in a real world election in over 90 years of use in Australia, 50 years plus in Ireland, and quite a few other places in recent times) mathematical possibilities which if a voter changed the order of their rankings, the outcome would change.  Since this never manifests in the real world, and since you would be required to have extensive and very precise poll data to determine the possibility manifesting, Instant Runoff Voting is largely immune to the psychologies that would inspire a voter to modify their vote in an insincere manner.  In other words, Instant Runoff Voting doesn't promote insincere voting to the extent that Range Voting or Approval Voting do.

    Arrow didn't consider non-ranked systems in his theorem because he never took these systems seriously.  There is more to voting than just imagined mathematical outcomes, as we are talking about groups of people and how they think and behave. It is too bad Arrow didn't include non-ranked systems in his analysis, as perhaps people wouldn't attempt to use this as evidence that they are somehow without flaw.

    I am a little disturbed at the attempt to imply Fidel Castro (a totalitarian communist) or Adolf Hitler (a totalitarian fascist) would win in an IRV election in America when they are not on the ballot, nor have they ever been candidates in America.  And as this article points out:  these inferences, while grossly alarmist at the core, are the IMAGININGS of the authors and all their own ideas, not based on real world elections, but computer simulations.  I can imagine Range Voting failing as well, and I don't have to create numbers from thin air to demonstrate it--i merely have to refer to principles of sociology and psychology, and how people will try to maximize their representation and winning in any system.  This apparently doesn't show up in their computer simulations with numbers pulled from imaginationland.

    Either way, to categorize Fairvote's mission as purely Instant Runoff Voting, when in fact they also promote Single Transferrable Voting and proportional representation systems for legislative, multi-member bodies, is just completely innacurate.  Fairvote also promotes DC voting rights (in congress), a national popular vote for President, and many other issues you can read for yourself on their Web Site:  www.fairvote.org . Fairvote is far from a single-issue advocacy group as they are painted in this article.

    Rate this comment: 12345

    anthonyviva
    08/19/2008
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    2/5
  • Spartan system fails one person, one vote criterion
    In Sparta, the person with the loudest voice would have a greater voice than others.  As would be the case if i voted insincerely in a range voting election, rating candidates 0 who were the opponents of my chosen candidate. In our representative republic, the people are all supposed to have an equal voice, and our ability to make noise is not created equal.  Not sure why this is cited as an example here, considering those details, but I am glad I don't live in Sparta, as i certainly don't have the loudest voice in my community, just the most persistent and often rational.
    Rate this comment: 12345

    anthonyviva
    08/19/2008
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    • Re: Spartan system fails one person, one vote criterion
      Good observation, it is definitely an unfair range voting system in the sense that some people will be louder than others. Hopefully this difference in ability isn't/wasn't significant between various factions of the population. It did seem to work for them for a fairly long time!

      Obviously we're not in support of giving different ranges to different voters, and unfortunately we were under space constraints, so this factual bit slipped out of the article as "obvious."
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      rcarback
      08/19/2008
      Posts:6
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      4/5
    • One person, one ballot
      Smith's Bayesian regret calculations factored in the insincere exaggeration you speak of, and Score Voting still dominated.

      And all deterministic voting methods are susceptible to that strategic behavior. With IRV, for instance, voters have an incentive to insincerely rank their favorite front-runner first place, even if he's not their favorite overall candidate.
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      brokenladder
      10/03/2008
      Posts:3
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      4/5
  • Anthony Lorenzo is confused
    It's amazing that Anthony Lorenzo has persisted in making these erroneous arguments against Score Voting (aka Range Voting) after being corrected so often by people like Warren Smith, the Princeton math Ph.D. who co-founded the Center for Range Voting.

    Smith's extensive Bayesian regret calculations show that Score Voting performs about as well with 100% strategic voters as IRV does with 100% honest voters, so that ought to be the nail in the coffin as far as Lorenzo's strategic voting issue.
    See http://rangevoting.org/StratHonMix.html

    But many voters prefer to be expressive, and for every voter who votes expressively, Score Voting becomes that much better than IRV for the average voter. Even with a mere 10% or so expressive voters, Score Voting begins to handily thump IRV - and we think it's plausible that a lot more people than that will choose expressiveness over strategy.

    But the contrast between Score Voting and IRV becomes even more stark when considering the real vulnerability of IRV to strategic voting. Lorenzo and other IRV advocates try to argue that strategic voting opportunities have never occurred in historical IRV elections, and that they are too hard to predict to be exploited. But this reasoning is confused and highly misleading.

    For one thing, very few elections have had their full ballot data released to the public, so most elections restrict analysis to mere inference of plausible scenarios. In other cases we have to look at traditional runoff elections, or other types of elections to make estimates of how they would have behaved under IRV. What data we do have suggests that the problems mentioned by IRV's critics are indeed real. (For instance this page About the 2007 Federal IRV elections in Australia.) Furthermore, statistical analysis and computer modeling of elections strongly suggest that opportunities for strategy are quite real with IRV.

    But even if such examples are rare, that in no way prevents a savvy voter from wanting to strategically downgrade weak candidates with IRV. It demonstrates lack of expertise on Lorenzo's part that he does not grasp that. Here's why.

    Say a voter prefers..

    m1 > m2 > .. > M1 > m3 > m4 > .. M2 > ..

    where the lowercase m's represent minor candidates and the uppercase M's represent major candidates. If m1 and m2 are people like Dennis Kucinich and Mike Gravel, a savvy voter knows they very likely won't win - but that they may spread the first-place votes enough that M1 -- "Obama" -- is eliminated early on, only to have one of the m's lose to M2 ("Clinton") in a later round. Such a voter would later feel the wasted vote syndrome, that he could have helped to at least get the "lesser evil" between the major candidates by raising that candidate to the top.

    This same feeling was observed by some large polls earlier in this year's primary process, when many people reported that they honestly preferred Clinton > Obama > Republicans, but would support Obama because they felt he had a better chance of beating the Republican. That same logic would compel them to insincerely vote Obama > Clinton > GOP (ignoring the others for simplicity) if it were an IRV race.

    The naive mistake people like Lorenzo always make is to assume that IRV strategy is only justifiable if voters know that, to use this case as an example, Clinton will lose to the Republican opponent. But on the contrary, they don't have to know that at all. All they have to have is evidence (e.g. polling data) that says which event is more likely. So in one final example, in an IRV election, you might prefer this..

    Kucinich > .. > Gravel > Obama > Clinton,

    but if Obama and Clinton are clearly the front-runners (which they were), then you'd want to vote

    Obama > Kucinich > .. > Gravel > Clinton

    Because you know that this almost certainly cannot hurt you, but may help you by preventing Obama from being knocked out.

    That these IRV advocates either do not understand this basic exercise is illustrative of their understanding of the subject of voting methods.

    Finally, Anthony Lorenzo is kidding himself if he thinks Score Voting advocates haven't thought about the subject of strategic voting already. Here are some pages he apparently forgot to mention.

    http://rangevoting.org/StratHonMix.html
    http://rangevoting.org/PleasantSurprise.html
    http://rangevoting.org/TarrIrv.html
    http://rangevoting.org/DH3.html
    http://rangevoting.org/Honesty.html
    http://rangevoting.org/HonStrat.html
    http://rangevoting.org/ShExpRes.html
    http://rangevoting.org/RVstrat1.html
    http://rangevoting.org/RVstrat2.html
    http://rangevoting.org/RVstrat3.html
    http://rangevoting.org/RVstrat4.html
    http://rangevoting.org/RVstrat5.html
    http://rangevoting.org/RVstrat6.html

    Clay Shentrup
    San Francisco, CA
    Rate this comment: 12345

    brokenladder
    08/20/2008
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    4/5
    • Re: Anthony Lorenzo is confused
      Yes, the Web Site quoted where i am "corrected" quotes me largely out of context and refuses to incorporate my full responses.  It is owned by the folks who are responding to my comments, i might add, and is highly biased in favor of their viewpoint.  One should certainly mention that as a disclaimer when quoting it.

      As such, I am sure Range Voting is better than what is used in my elections. I am just disagreeing on the point that IRV is inferior to range voting, or somehow seriously flawed.  That is all i disagree with here.  I would also love to see some of the advocates for range voting actually organize an organization that can put forward range voting for real world elections involving people, not mathematical simulations only.  I would look forward to seeing some data based on actual use, rather than purely mathematical theory.
      Rate this comment: 12345

      anthonyviva
      08/24/2008
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      2/5
      • Re: Anthony Lorenzo is confused
        Saying that ScoreVoting.net is biased is an ad hominem. Creationists can say that a site like TalkOrigins.org is "biased" in favor of evolution, but that does not refute the scientific evidence presented therein. If you have any evidence to present, feel free to present it. But we've presented an enormous amount of evidence that Score Voting (aka Range Voting) is vastly superior to IRV.

        Also I am a little tired of hearing this confused comment about looking at real elections instead of "mathematical theory". You cannot measure Bayesian regret with real elections, because they are rare and, more importantly, because we cannot read human minds.

        The bottom line is that the results of Warren Smith's Bayesian regret calculations show Score Voting to be better than IRV by a very large margin, and criticisms that they are not sufficiently realistic are countered by the consistency of those results among all 720 different combinations of election parameters. For instance, you can turn the strategy knob all the way from 0% (all voters are expressive) to 100% (all voters are strategic, even if it means misrepresenting their preferences), and the results are consistent among that whole range.

        So you can't say that wasn't realistic. We use the whole range of values that possibly could exist in reality.

        Despite the best of intentions, Anthony's pattern of behavior is to simply disregard these complex aspects of voting theory and repeat the same talking points, like the "use reality, not theory" argument I just addressed.
        Rate this comment: 12345

        brokenladder
        10/03/2008
        Posts:3
        Avg Rating:
        4/5

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Scoring the Candidates
Range voting would prevent third-party spoilers--and give voters more say.
By Alan T. Sherman '87, Warren D. Smith '84, and Richard T. Carback III
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When Pam Melroy, SM '84, commands the space shuttle, laughter is an essential part of the voyage.
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