Arrow’s Impossibility Theorem
Definition
Arrow's Impossibility Theorem states that no rank-order voting system can meet all of a specified set of criteria for fairness. It proves the inherent limitations and trade-offs in collective decision-making processes.
5 Must Know Facts For Your Next Test
- Proposed by economist Kenneth Arrow in 1951.
- The theorem applies to any voting method that ranks preferences.
- It specifies three fairness criteria: non-dictatorship, unrestricted domain, and independence of irrelevant alternatives.
- Arrow's Theorem demonstrates the impossibility of creating a perfect voting system that satisfies all three criteria simultaneously.
- This theorem is also known as the General Impossibility Theorem.
Review Questions
- What are the three fairness criteria outlined in Arrow's Impossibility Theorem?
- Who proposed Arrow's Impossibility Theorem and in what year?
- Why does Arrow's Impossibility Theorem suggest about creating an ideal voting system?
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Related terms
Non-Dictatorship: A condition where no single voter possesses the power to always determine the group's preference.
Unrestricted Domain: A criterion stating that every possible order of preferences should be allowed among voters.
Independence of Irrelevant Alternatives: A principle stating that if a preference ranking between two options changes, it should only be influenced by those two options and not by changes in other irrelevant alternatives.
