Pareto efficiency: Difference between revisions
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The '''Pareto criterion''' is a basic criterion for evaluating [[voting system|voting systems]]. It can be defined in this way: |
The '''Pareto criterion''' is a basic criterion for evaluating [[voting system|voting systems]]. It can be defined in this way: |
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{{definition|If every voter |
{{definition|If every voter prefers alternative X over alternative Y, then the system prefers X over Y}} |
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This criterion is important in the context of [[Arrow's impossibility theorem]]. |
This criterion is important in the context of [[Arrow's impossibility theorem]]. |
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Revision as of 16:47, 29 November 2019
The Pareto criterion is a basic criterion for evaluating voting systems. It can be defined in this way:
If every voter prefers alternative X over alternative Y, then the system prefers X over Y
This criterion is important in the context of Arrow's impossibility theorem.
Virtually every devised election method satisfies this criterion. An example of a method which would fail it would be Random Candidate, where some candidate is elected at random, regardless of the submitted votes.