Participation criterion: Difference between revisions
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{{wikipedia}} |
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This is the criteria that there is no strategic advantage to not vote. Typically a voter does not know they are in this situation and if they do they can potentially avoid the problem with [[Tactical voting]] |
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== Statement of Criterion == |
== Statement of Criterion == |
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the winner from X to Y.}} |
the winner from X to Y.}} |
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== Variants == |
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By voting, you cannot cause X to be elected instead of Y (with all other winners staying the same) if you scored Y higher than X. One consequence of this criteria, is that by voting, you can never get a result that is less desirable according to your ballot then a result that is more desirable according to your ballot. The difference between this criterion and the strong Strong Participation criterion is that because unless there was an infinite range for you to score candidates on (you are scoring candidates on infinite sliding bars), due to the approximations you make when expressing your utilities on a finite number of scores, your ballot can disagree with you about whether outcome X is better than outcome Y. |
By voting, you cannot cause X to be elected instead of Y (with all other winners staying the same) if you scored Y higher than X. One consequence of this criteria, is that by voting, you can never get a result that is less desirable according to your ballot then a result that is more desirable according to your ballot. The difference between this criterion and the strong Strong Participation criterion is that because unless there was an infinite range for you to score candidates on (you are scoring candidates on infinite sliding bars), due to the approximations you make when expressing your utilities on a finite number of scores, your ballot can disagree with you about whether outcome X is better than outcome Y. |
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(Described here: [https://rangevoting.org/QualityMulti.html#faildesid "Optimal proportional representation" multiwinner voting systems I: methods, algorithms, advantages, and inherent flaws]) |
(Described here: [https://rangevoting.org/QualityMulti.html#faildesid "Optimal proportional representation" multiwinner voting systems I: methods, algorithms, advantages, and inherent flaws]) |
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⚫ | This is a weaker form of the [[participation criterion]]. It states that for any set of ballots, an extra voter with a given preference set must be able to cast a ballot which is semi-honest and meaningfully expressive, without making the result worse. Meaningfully expressive means that if the voter prefers some set of candidates to the winner, the non-harmful ballot must be able to express that preference. |
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== Complying Methods == |
== Complying Methods == |
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This Criteria is important in the context of the [[Balinski–Young theorem]]. Failing the participation criterion is an an example of failing [[Population monotonicity]]. |
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[[Plurality voting]], [[Approval voting]], [[Cardinal Ratings]], [[Borda count]], and Woodall's [[Descending Acquiescing Coalitions|DAC]] and [[Descending Solid Coalitions|DSC]] methods all pass the Participation Criterion. [[Condorcet method | Condorcet methods]], [[Majority Choice Approval]], and [[IRV]] fail. |
[[Plurality voting]], [[Approval voting]], [[Cardinal Ratings]], [[Borda count]], and Woodall's [[Descending Acquiescing Coalitions|DAC]] and [[Descending Solid Coalitions|DSC]] methods all pass the Participation Criterion. [[Condorcet method | Condorcet methods]], [[Majority Choice Approval]], and [[IRV]] fail. |
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All Monroe type Multi-member systems fail participation. |
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''Some parts of this article are derived with permission from text at http://electionmethods.org'' |
''Some parts of this article are derived with permission from text at http://electionmethods.org'' |
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⚫ | This is a weaker form of the [[participation criterion]]. It states that for any set of ballots, an extra voter with a given preference set must be able to cast a ballot which is semi-honest and meaningfully expressive, without making the result worse. Meaningfully expressive means that if the voter prefers some set of candidates to the winner, the non-harmful ballot must be able to express that preference. |
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== See also == |
== See also == |
Revision as of 15:43, 22 March 2020
This is the criteria that there is no strategic advantage to not vote. Typically a voter does not know they are in this situation and if they do they can potentially avoid the problem with Tactical voting
Statement of Criterion
Adding one or more ballots that vote X over Y should never change the winner from X to Y.
Variants
Weak Participation criterion
By voting, you cannot cause X to be elected instead of Y (with all other winners staying the same) if you scored Y higher than X. One consequence of this criteria, is that by voting, you can never get a result that is less desirable according to your ballot then a result that is more desirable according to your ballot. The difference between this criterion and the strong Strong Participation criterion is that because unless there was an infinite range for you to score candidates on (you are scoring candidates on infinite sliding bars), due to the approximations you make when expressing your utilities on a finite number of scores, your ballot can disagree with you about whether outcome X is better than outcome Y.
(Described here: "Optimal proportional representation" multiwinner voting systems I: methods, algorithms, advantages, and inherent flaws)
Semi-honest participation criterion
This is a weaker form of the participation criterion. It states that for any set of ballots, an extra voter with a given preference set must be able to cast a ballot which is semi-honest and meaningfully expressive, without making the result worse. Meaningfully expressive means that if the voter prefers some set of candidates to the winner, the non-harmful ballot must be able to express that preference.
Complying Methods
This Criteria is important in the context of the Balinski–Young theorem. Failing the participation criterion is an an example of failing Population monotonicity.
Plurality voting, Approval voting, Cardinal Ratings, Borda count, and Woodall's DAC and DSC methods all pass the Participation Criterion. Condorcet methods, Majority Choice Approval, and IRV fail.
All Monroe type Multi-member systems fail participation.
Some parts of this article are derived with permission from text at http://electionmethods.org
See also
- Voting system
- Monotonicity criterion
- Condorcet Criterion
- Generalized Condorcet criterion
- Strategy-Free criterion
- Generalized Strategy-Free criterion
- Strong Defensive Strategy criterion
- Weak Defensive Strategy criterion
- Favorite Betrayal criterion
- Summability criterion