Pareto efficiency: Difference between revisions
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{{wikipedia|Pareto efficiency}} |
{{wikipedia|Pareto efficiency}} |
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'''Pareto efficiency''' (frequently referred to as the "'''Pareto criterion'''" or "'''Unanimity criterion'''" in the [[election method]] context) 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 prefers alternative X over alternative Y, then the |
{{definition|If every voter prefers alternative X over alternative Y, then the election method 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]], since it was one of Arrow's criteria in the theorem. |
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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. |
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. |
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