Arrow's theorem

proper noun

A theorem stating that no voting system can be perfectly fair in all circumstances. Specifically, when voters have three or more distinct alternatives, no ranked voting electoral system can convert the ranked preferences of individuals into a community-wide (complete and transitive) ranking while also meeting the specified set of criteria: unrestricted domain, non-dictatorship, Pareto efficiency, and independence of irrelevant alternatives.

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Meanings

proper noun
  1. governmentA theorem stating that no voting system can be perfectly fair in all circumstances. Specifically, when voters have three or more distinct alternatives, no ranked voting electoral system can convert the ranked preferences of individuals into a community-wide (complete and transitive) ranking while also meeting the specified set of criteria: unrestricted domain, non-dictatorship, Pareto efficiency, and independence of irrelevant alternatives.

Origin

Named after economist Kenneth Arrow, who demonstrated the theorem in his doctoral thesis and popularized it in his 1951 book Social Choice and Individual Values.

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Cite this entry
APA

Arrow's theorem. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Arrow's%20theorem

MLA

“Arrow's theorem.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Arrow's%20theorem. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “Arrow's theorem,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Arrow's%20theorem.

Source: Arrow's theorem on Wiktionary, CC BY-SA 4.0.