We investigate how individuals think groups should aggregate members' ordinal preferences - that is, how they interpret "the will of the people." In an experiment, we elicit revealed attitudes toward ordinal preference aggregation and classify subjects according to the rules they apparently...

We propose the concept of level r consensus as a useful property of a preference profile which considerably enhances the stability of social choice. This concept involves a weakening of unanimity, the most extreme form of consensus. It is shown that if a preference profile exhibits level r...

We reappraise the Arrow problem by studying the aggregation of choice functions. We do so in the general framework of judgment aggregation, in which choice functions are naturally representable by specifying, for each menu A and each alternative x in A, whether x is choosable from A, or not. Our...

Consider a setting in which individual strict preferences need to be aggregated into a social strict preference relation. For two alternatives and an odd number of agents, it follows from May’s Theorem that the majority aggregation rule is the only one satisfying anonymity, neutrality, and...

Politicians, CEOs and various other types of dictators make social choices that influence both their own and others' welfare. When a dictator's preferred alternative differs from recipients', it is unclear which preferences they aggregate and how they determine this set of admissible...

Call a mechanism that associates each profile of preferences over candidates to an ambiguous act an Ambiguous Social Function (ASCF). This paper studies the strategy-proofness of ASCFs. We find that an ASCF is unanimous and strategyproof if and only if there exists a nonempty subset of voters,...

We consider functions that assign to each evaluation profile a preference system or a list of menu dependent preferences. The rule by which such an assignment takes place is said to be a menu dependent preference functional (MDPFL). We extend the concepts of invariance under individual cardinal...

This paper is concerned with preference-aggregation rules satisfying desirable efficiency and solidarity requirements. We formulate weaker versions of existing solidarity axioms and show how they imply, in conjunction with strategy-proofness, the existence of reference outcomes holding...

When individual preferences can express relative intensities, the scope for social decision mechanisms is enlarged. We show that ethical welfare operations then arise in a uniform, constitutional manner, in both finite and infinite contexts.We focus on quaternary preferences as representatives...