Rated voting

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(Redirected from
Cardinal voting
)
A theoretical ballot with the instructions "Rate each between negative ten and ten." There are five options, each one with a number corresponding to it. The numbers, from top to bottom, are seven, ten, negative three, zero, and ten.
On a rated ballot, the voter may rate each choice independently.
A theoretical ballot with the instructions "Vote for any number of options." Two choices are marked, three are not. There is no difference between the markings.
An approval voting ballot does not require ranking or exclusivity.

Rated voting refers to any electoral system which allows the voter to give each candidate an independent evaluation, typically a rating or grade.[1] These are also referred to as cardinal, evaluative, or graded voting systems.[citation needed] Cardinal methods (based on cardinal utility) and ordinal methods (based on ordinal utility) are the two modern categories of voting systems.[2][3][4]

Variants

A scan of a real ballot that was already marked, with instructions to mark each candidate from A to F, where A is best. Spaces left blank are considered as F. The options from top to bottom are Eleanor Roosevelt, graded C, Cesar Chavez, graded B, Walter Lum, graded C, John Hancock, graded F, Martin Luther King Jr, graded B, and Nancy Reagan, graded A.
A majority judgment ballot is based on grades like those used in schools.

There are several voting systems that allow independent ratings of each candidate. For example:

In addition, every cardinal system can be converted into a proportional or semi-proportional system by using Phragmen's voting rules or Thiele's voting rules. Examples include:

Relationship to rankings

Ratings ballots can be converted to ranked/preferential ballots, assuming equal ranks are allowed. For example:

Rating (0 to 99) Preference order
Candidate A 99 First
Candidate B 55 Second
Candidate C 20 Third
Candidate D 20 Third

However, rankings cannot be converted to ratings, since ratings carry more information about strength of preferences, which is destroyed when converting to rankings. Rated voting allows voters to "skip" ranks.

Analysis

Cardinal voting methods are not subject to Arrow's impossibility theorem,[12] which proves that ranked-choice voting methods can be manipulated by strategic nominations.[13] However, since one of these criteria (called "universality") implicitly requires that a method be ordinal, not cardinal, Arrow's theorem does not apply to cardinal methods.[14][13]

Others, however, argue that ratings are fundamentally invalid, because meaningful interpersonal comparisons of utility are impossible.[15] This was Arrow's original justification for only considering ranked systems,[16] but later in life he stated that cardinal methods are "probably the best."[17]

Psychological research has shown that cardinal ratings (on a numerical or Likert scale, for instance) are more valid and convey more information than ordinal rankings in measuring human opinion.[18][19][20][21]

Cardinal methods can satisfy the Condorcet winner criterion, usually by combining cardinal voting with a first stage (as in Smith//Score).

Strategic voting

The weighted mean utility theorem gives the optimal strategy for cardinal voting under most circumstances, which is to give the maximum score for all options with an above-average

sincere ranking of candidates on the ballot (a property that is impossible for ranked-choice voting, by the Gibbard–Satterthwaite theorem
).

Most cardinal methods, including

Condorcet and Smith criteria if voters behave strategically.[citation needed] As a result, cardinal methods with strategic voters tend to produce results results similar to Condorcet methods with honest voters.[citation needed
]

See also

References

  1. ISSN 0176-2680
    . A key feature of evaluative voting is a form of independence: the voter can evaluate all the candidates in turn ... another feature of evaluative voting ... is that voters can express some degree of preference.
  2. . Ordinal utility is a measure of preferences in terms of rank orders—that is, first, second, etc. ... Cardinal utility is a measure of preferences on a scale of cardinal numbers, such as the scale from zero to one or the scale from one to ten.
  3. ^ "Ordinal Versus Cardinal Voting Rules: A Mechanism Design Approach".
  4. SSRN 1116545. {{cite journal}}: Cite journal requires |journal= (help
    )
  5. ^ "Score Voting". The Center for Election Science. 21 May 2015. Retrieved 10 December 2016. 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.
  6. ^ . Retrieved 15 May 2018. Specific UV rules that have been proposed are approval voting, allowing the scores 0, 1; range voting, allowing all numbers in an interval as scores; evaluative voting, allowing the scores −1, 0, 1.
  7. SSRN 608821. I favor 'evaluative voting' under which a voter can vote for or against any alternative, or abstain. {{cite journal}}: Cite journal requires |journal= (help
    )
  8. . under CAV he has three options—cast one vote in favor, abstain, or cast one vote against.
  9. ^ "STAR Voting". Equal Vote Coalition. Archived from the original on 1 July 2020. Retrieved 14 July 2018.
  10. ^ "STAR voting an intriguing innovation". The Register Guard. Retrieved 14 July 2018.
  11. ^ "Are We Witnessing the Cutting Edge of Voting Reform?". IVN.us. 1 February 2018. Retrieved 14 July 2018.
  12. SSRN 1116545. {{cite journal}}: Cite journal requires |journal= (help
    )
  13. ^ a b "How I Came to Care About Voting Systems". The Center for Election Science. 21 December 2011. Retrieved 10 December 2016. But Arrow only intended his criteria to apply to ranking systems.
  14. ^ "Interview with Dr. Kenneth Arrow". The Center for Election Science. 6 October 2012. Archived from the original on 2018-10-27. Retrieved 2016-12-10. CES: you mention that your theorem applies to preferential systems or ranking systems. ... But the system that you're just referring to, Approval Voting, falls within a class called cardinal systems. ... Dr. Arrow: And as I said, that in effect implies more information. ... I'm a little inclined to think that score systems where you categorize in maybe three or four classes probably (in spite of what I said about manipulation) is probably the best.
  15. ^ "Why Not Ranking?". The Center for Election Science. 31 May 2016. Retrieved 22 January 2017. Many voting theorists have resisted asking for more than a ranking, with economics-based reasoning: utilities are not comparable between people. ... But no economist would bat an eye at asking one of the A voters above whether they'd prefer a coin flip between A and B winning or C winning outright...
  16. ^ "Modern economic theory has insisted on the ordinal concept of utility; that is, only orderings can be observed, and therefore no measurement of utility independent of these orderings has any significance. In the field of consumer's demand theory the ordinalist position turned out to create no problems; cardinal utility had no explanatory power above and beyond ordinal. Leibniz' Principle of the identity of indiscernibles demanded then the excision of cardinal utility from our thought patterns." Arrow (1967), as quoted on p. 33 by Racnchetti, Fabio (2002), "Choice without utility? Some reflections on the loose foundations of standard consumer theory", in Bianchi, Marina (ed.), The Active Consumer: Novelty and Surprise in Consumer Choice, Routledge Frontiers of Political Economy, vol. 20, Routledge, pp. 21–45
  17. ^ "Interview with Dr. Kenneth Arrow". The Center for Election Science. 6 October 2012. Archived from the original on 2018-10-27. Retrieved 2016-12-10. CES: you mention that your theorem applies to preferential systems or ranking systems. ... But ... Approval Voting, falls within a class called cardinal systems. ... Dr. Arrow: And as I said, that in effect implies more information. ... I'm a little inclined to think that score systems where you categorize in maybe three or four classes ... is probably the best.
  18. ISSN 0022-1015
    . the scale-of-values method can be used for approximately the same purposes as the order-of-merit method, but that the scale-of-values method is a better means of obtaining a record of judgments
  19. . The extremely high degree of correspondence found between ranking and rating averages ... does not leave any doubt about the preferability of the rating method for group description purposes. The obvious advantage of rating is that while its results are virtually identical to what is obtained by ranking, it supplies more information than ranking does.
  20. . Many value researchers have assumed that rankings of values are more valid than ratings of values because rankings force participants to differentiate more incisively between similarly regarded values ... Results indicated that ratings tended to evidence greater validity than rankings within moderate and low-differentiating participants. In addition, the validity of ratings was greater than rankings overall.
  21. . the test-retest reliabilities of the ranking items were slightly higher than were those of the rating items, but construct validities were lower. Because validity is the most important consideration ... the findings of the present research support the use of the rating format in assessing health values. ... added benefit of item independence, which allows for greater flexibility in statistical analyses. ... also easier than ranking items for respondents to complete.
  22. ^ Approval Voting, Steven J. Brams, Peter C. Fishburn, 1983