Approval Voting under Dichotomous Preferences: A Catalogue of Characterizations

With D. Peters
Journal of Economic Theory, 205, 2022
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Approval voting allows every voter to cast a ballot of approved alternatives and chooses the alternatives with the largest number of approvals. Due to its simplicity and superior theoretical properties, it is a serious contender for use in real-world elections. We support this claim by giving eight characterizations of approval voting. All our results involve the consistency axiom, which requires choices to be consistent across different electorates. In addition, we consider strategyproofness, agreement with majority opinions, independence of cloned alternatives, and invariance under removing inferior alternatives. We prove our results by reducing them to a single base theorem, for which we give a simple and intuitive proof.Approval voting allows every voter to cast a ballot of approved alternatives and chooses the alternatives with the largest number of approvals. Due to its simplicity and superior theoretical properties, it is a serious contender for use in real-world elections. We support this claim by giving eight characterizations of approval voting. All our results involve the consistency axiom, which requires choices to be consistent across different electorates. In addition, we consider strategyproofness, agreement with majority opinions, independence of cloned alternatives, and invariance under removing inferior alternatives. We prove our results by reducing them to a single base theorem, for which we give a simple and intuitive proof.