Judgment Aggregation by Quota Rules: Majority Voting Generalized
نویسنده
چکیده
The widely discussed discursive dilemmashows that majority voting in a group of individuals on logically connected propositions may produce irrational collective judgments. We generalize majority voting by considering quota rules, which accept each proposition if and only if the number of individuals accepting it exceeds a given threshold, where di¤erent thresholds may be used for di¤erent propositions. After characterizing quota rules, we prove necessary and su¢ cient conditions on the required thresholds for various collective rationality requirements. We also consider sequential quota rules, which ensure collective rationality by adjudicating propositions sequentially and letting earlier judgments constrain later ones. Sequential rules may be path-dependent and strategically manipulable. We characterize pathindependence and prove its essential equivalence to strategy-proofness. Our results shed light on the rationality of simple-, super-, and sub-majoritarian decision-making.
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