A Characterization of Plurality-Like Rules Based on Non-Manipulability, Restricted Efficiency, and Anonymity

A society needs to decide which issues (laws, public projects, public facilities, etc.) in an agenda to accept. The decision can be any subset of the agenda but must reflect the preferences of its members, which are assumed to be ¡°separable weak orderings¡±. We characterize a family of ¡°plurality-like¡± rules based on strategy-proofness, restricted efficiency, anonymity, and two weak axioms pertaining to the variable agenda feature of our model, called dummy independence and division indifference. We also characterize a wide spectrum of rules dropping anonymity or restricted efficiency.