Wikipedia

Score voting

Score voting,sometimes calledrange voting,is anelectoral systemfor single-seat elections. Voters give each candidate a numerical score, and the candidate with the highest average score is elected.[1]Score voting includes the well-knownapproval voting(used to calculateapproval ratings), but also lets voters give partial (in-between) approval ratings to candidates.[2]

Usage

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Political use

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Historical

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A crude form of score voting was used in some elections in ancientSparta,by measuring how loudly the crowd shouted for different candidates.[3][4][5]This has a modern-day analog of usingclapometersin some television shows and the judging processes of some athletic competitions.

Beginning in the 13th century, theRepublic of Veniceelected theDoge of Veniceusing a multi-stage process with multiple rounds of score voting. This may have contributed to the Republic's longevity, being partly responsible for its status as the longest-liveddemocracyin world history.[6][7]Score voting was used inGreeklegislative elections beginning in 1864, during which time it had amany-party system;it was replaced withparty-list proportional representationin 1923.[8]

According to Steven J. Brams, approval was used for some elections in 19th century England.[9]

Current

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Score voting is used to elect candidates who represent parties inLatvia'sSaeima(parliament) in anopen listsystem.[10]

Theselection processfor theSecretary-General of the United Nationsuses a variant on a three-point scale ( "Encourage", "Discourage", and "No Opinion" ), withpermanent members of the United Nations Security Councilholding a veto over any candidate.[11][12]

Proportional score voting was used inSwedish electionsin the early 20th century, prior to being replaced byparty-list proportional representation.It is still used for local elections.

On a score ballot, the voter scores all the candidates.
Governor
Candidates 		Score each candidate by filling in
a number (0 is worst; 9 is best)
1: Candidate A → ⓿①②③④⑤⑥⑦⑧⑨
2: Candidate B → ⓪①②③④⑤⑥⑦⑧❾
3: Candidate C → ⓪①②③④⑤⑥❼⑧⑨

In 2018,Fargo, North Dakota,passed a local ballot initiative adoptingapproval votingfor the city's local elections, becoming the first US city to adopt the method.[13][14][15]

Score voting is used by theGreen Party of Utahto elect officers, on a 0–9 scale.[16]

Non-political use

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Members ofWikipedia's Arbitration Committeeare elected based on a three-point scale ( "Support", "Neutral", "Oppose" ).[17]

Non-governmental uses of score voting are common, such as inLikert scalesforcustomer satisfactionsurveys and mechanism involving users rating a product or service in terms of "stars" (such as rating movies onIMDb,products atAmazon,apps in the iOS orGoogle Playstores, etc.). Judged sports such asgymnasticsgenerally rate competitors on a numeric scale.

A multi-winner proportional variant calledThiele's methodor reweighted range voting is used to select five nominees for theAcademy Award for Best Visual Effectsrated on a 0–10 scale.[18]

Example

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Suppose thatTennesseeis holding an election on the location of itscapital.The population is concentrated around four major cities.All voters want the capital to be as close to them as possible.The options are:

  • Memphis,the largest city, but far from the others (42% of voters)
  • Nashville,near the center of the state (26% of voters)
  • Chattanooga,somewhat east (15% of voters)
  • Knoxville,far to the northeast (17% of voters)

The preferences of each region's voters are:

42% of voters
Far-West 		26% of voters
Center 		15% of voters
Center-East 		17% of voters
Far-East
  1. Memphis
  2. Nashville
  3. Chattanooga
  4. Knoxville
  1. Nashville
  2. Chattanooga
  3. Knoxville
  4. Memphis
  1. Chattanooga
  2. Knoxville
  3. Nashville
  4. Memphis
  1. Knoxville
  2. Chattanooga
  3. Nashville
  4. Memphis

Suppose that 100 voters each decided to grant from 0 to 10 points to each city such that their most liked choice got 10 points, and least liked choice got 0 points, with the intermediate choices getting an amount proportional to their relative distance.

Voter from/
City Choice 		Memphis Nashville Chattanooga Knoxville Total
Memphis 420 (42 × 10) 0 (26 × 0) 0 (15 × 0) 0 (17 × 0) 420
Nashville 168 (42 × 4) 260 (26 × 10) 90 (15 × 6) 85 (17 × 5) Y603
Chattanooga 84 (42 × 2) 104 (26 × 4) 150 (15 × 10) 119 (17 × 7) 457
Knoxville 0 (42 × 0) 52 (26 × 2) 90 (15 × 6) 170 (17 × 10) 312

Nashville, the capital in real life, likewise wins in the example.

For comparison, note that traditional first-past-the-post would elect Memphis, even though most citizens consider it the worst choice, because 42% is larger than any other single city.Instant-runoff votingwould elect the 2nd-worst choice (Knoxville), because the central candidates would be eliminated early (and Chattanooga voters preferring Knoxville above Nashville). Inapproval voting,with each voter selecting their top two cities, Nashville would win because of the significant boost from Memphis residents.

Properties

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Score voting allows voters to express preferences of varying strengths, making it arated votingsystem.

Score voting is not vulnerable to theless-is-more paradox,i.e. raising a candidate's rating can never hurt their chances of winning. Score also satisfies theparticipation criterion,i.e. a candidate can never lose as a result of voters turning out to support them. Score voting satisfiesindependence of irrelevant alternatives,and does not tend to exhibitspoiler effects.

It does not satisfy theCondorcet criterion,i.e. the method does not always agree with themajority rule.However, when voters all vote strategically, basing their votes onpollingor pastelectionresults, the majority-preferred candidate will win.[19]

Strategy

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See also:Tactical voting § Score voting

Ideal scorevoting strategyfor well-informed voters is generally identical to their optimalapproval votingstrategy; voters will want to give their least and most favorite candidates a minimum and a maximum score, respectively. The game-theoretical analysis shows that this claim is not fully general, but holds in most cases.[20]Another strategic voting tactic is given by the weighted mean utility theorem, maximum score for all candidates preferred compared to the expected winners weighted with winning probability and minimum score for all others.[21]

Papers have which found that "experimental results support the concept of bias toward unselfish outcomes in large elections." The authors observed what they termed ethical considerations dominating voter behavior as pivot probability decreased. This would imply that larger elections, or those perceived as having a wider margin of victory, would result in fewer tactical voters.[22]

How voters precisely grade candidates is a topic that is not fully settled, although experiments show that their behavior depends on the grade scale, its length, and the possibility to give negative grades.[23]

STAR voting(Score Then Automatic Runoff) is a variant proposed to address some concerns about strategic exaggeration in score voting. Under this system, each voter may assign a score (from 0 to the maximum) to any number of candidates. Of the two highest-scoring candidates, the winner is the one most voters ranked higher.[24]The runoff step was introduced to mitigate the incentive to exaggerate ratings in ordinary score voting.[25][26]

Advocacy

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Albert Heckscher was one of the earliest proponents, advocating for a form of score voting he called the "immanent method" in his 1892 dissertation, in which voters assign any number between -1 and +1 to each alternative, simulating their individual deliberation.[27][28][29]

Currently, score voting is advocated byThe Center for Election Science.[citation needed]Since 2014, the Equal Vote Coalition advocates a variant method (STAR) with an extra second evaluation step to address some of the criticisms of traditional score voting.[30][31]

See also

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Notes

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  1. ^"Score Voting".The Center for Election Science.2015-05-21.Retrieved2016-12-10.Simplified forms of score voting automatically give skipped candidates the lowest possible score for the ballot they were skipped. Other forms have those ballots not affect the candidate's rating at all. Those forms not affecting the candidates rating frequently make use of quotas. Quotas demand a minimum proportion of voters rate that candidate in some way before that candidate is eligible to win.
  2. ^Baujard, Antoinette; Igersheim, Herrade; Lebon, Isabelle; Gavrel, Frédéric; Laslier, Jean-François (2014-06-01)."Who's favored by evaluative voting? An experiment conducted during the 2012 French presidential election"(PDF).Electoral Studies.34:131–145.doi:10.1016/j.electstud.2013.11.003.Archived fromthe original(PDF)on 2021-04-10.Retrieved2019-12-22.voting rules in which the voter freely grades each candidate on a pre-defined numerical scale... also called utilitarian voting
  3. ^James S. Fishkin: The Voice of the People: Public Opinion & Democracy, Yale University Press 1995
  4. ^Girard, C. (2010). "Going from Theory to Practice: The Mixed Success of Approval Voting". In Laslier, Jean-François; Sanver, M. Remzi (eds.).Handbook on Approval Voting.Studies in Choice and Welfare. Springer Berlin Heidelberg. pp. 15–17.doi:10.1007/978-3-642-02839-7_3.ISBN9783642028380.
  5. ^Stille, Alexander (2001-06-02)."Adding Up the Costs of Cyberdemocracy".New York Times.Retrieved2009-10-03.
  6. ^Lines, Marji (1986). "Approval Voting and Strategy Analysis: A Venetian Example".Theory and Decision.20(2): 155–172.doi:10.1007/BF00135090.S2CID121512308.
  7. ^Mowbray, Miranda; Gollmann, Dieter (July 2007).Electing the Doge of Venice: analysis of a 13th Century protocol(PDF).IEEE Computer Security Foundations Symposium. Venice, Italy.Archived(PDF)from the original on October 9, 2022.
  8. ^Mavrogordatos, George Th. (1983).Stillborn Republic: Social Coalitions and Party Strategies in Greece 1922–1936.University of California Press. pp. 351–352.
  9. ^Brams, Steven J. (April 1, 2006).The Normative Turn in Public Choice(PDF)(Speech). Presidential Address to Public Choice Society. New Orleans, Louisiana. Archived fromthe original(PDF)on May 31, 2010.RetrievedMay 8,2010.
  10. ^"14. SAEIMAS VĒLĒŠANAS".sv2022.cvk.lv.Retrieved2024-04-30.
  11. ^"The" Wisnumurti Guidelines "for Selecting a Candidate for Secretary-General"(PDF).Archived fromthe original(PDF)on February 27, 2008.RetrievedNovember 30,2007.
  12. ^Tharoor, Shashi (October 21, 2016)."The inside Story of How I Lost the Race for the UN Secretary-General's Job in 2006".OPEN Magazine.Archived fromthe originalon July 21, 2019.RetrievedMarch 6,2019.
  13. ^One of America's Most Famous Towns Becomes First in the Nation to Adopt Approval VotingArchivedNovember 7, 2018, at theWayback Machine,accessed November 7, 2018
  14. ^Moen, Mike (June 10, 2020)."Fargo Becomes First U.S. City to Try Approval Voting".Public News Service.RetrievedDecember 3,2020.
  15. ^Piper, Kelsey (November 15, 2018)."This city just approved a new election system never tried before in America".Vox.RetrievedJuly 8,2020.
  16. ^"Utah Green Party Hosts Dr. Stein; Elects New Officers".Independent Political Report.2017-06-27.Retrieved2017-09-14.Using the following Range Voting System, the Green Party of Utah elected a new slate of officers
  17. ^"Wikipedia:Arbitration Committee Elections December 2017".Wikipedia.2018-03-28.
  18. ^"89TH ANNUAL ACADEMY AWARDS OF MERIT"(PDF).2016. RULE TWENTY-TWO SPECIAL RULES FOR THE VISUAL EFFECTS AWARD.Five productions shall be selected using reweighted range voting to become the nominations for final voting for the Visual Effects award.
  19. ^Laslier, J.-F. (2006)"Strategic approval voting in a large electorate",IDEP Working PapersNo. 405 (Marseille, France: Institut d'Économie Publique)
  20. ^Nunez, Matias; Laslier, Jean-François (2014)."Preference intensity representation: strategic overstating in large elections"(PDF).Social Choice and Welfare.42(2): 313–340.doi:10.1007/s00355-013-0728-0.S2CID5738643.
  21. ^Approval Voting, Steven J. Brams, Peter C. Fishburn, 1983
  22. ^Feddersen, Timothy; Gailmard, Sean; Sandroni, Alvaro (2009). "Moral Bias in Large Elections: Theory and Experimental Evidence".The American Political Science Review.103(2): 175–192.doi:10.1017/S0003055409090224.JSTOR27798496.S2CID55173201.
  23. ^Baujard, Antoinette; Igersheim, Herrade; Lebon, Isabelle; Gavrel, Frédéric; Laslier, Jean-François (2014)."How voters use grade scales in evaluative voting"(PDF).European Journal of Political Economy.55:14–28.doi:10.1016/j.ejpoleco.2017.09.006.
  24. ^"Equal Vote Coalition".Retrieved2017-04-05.
  25. ^"Score Runoff Voting: The New Voting Method that Could Save Our Democratic Process".IVN.us.2016-12-08.Retrieved2017-04-05.
  26. ^"Strategic SRV? - Equal Vote Coalition".Equal Vote Coalition.Retrieved2017-04-05.
  27. ^Lagerspetz, Eerik (2014-06-01). "Albert Heckscher on collective decision-making".Public Choice.159(3–4): 327–339.doi:10.1007/s11127-014-0169-z.ISSN0048-5829.S2CID155023975.
  28. ^Eerik, Lagerspetz (2015-11-26).Social choice and democratic values.Cham. p. 109.ISBN9783319232614.OCLC930703262.{{cite book}}:CS1 maint: location missing publisher (link)
  29. ^Heckscher, Albert Gottlieb (1892).Bidrag til Grundlæggelse af en Afstemningslære: om Methoderne ved Udfindelse af Stemmeflerhed i Parlamenter(in Danish).
  30. ^"About The Equal Vote Coalition".Equal Vote Coalition.Retrieved2018-03-29.
  31. ^"STAR Voting campaign".Retrieved2019-09-02.
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