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...

In this paper we consider the exogenous indifference classes model of Barberá and Ehlers (2011) and Sato (2009) and analyze further the relationship between the structure of indifference classes across agents and dictatorship results. The key to our approach is the pairwise partition graph. We...

Condorcet domains are sets of linear orders with the property that, whenever the preferences of all voters of a society belong to this set, their majority relation has no cycles. We observe that, without loss of generality, every such domain can be assumed to be closed in the sense that it...

The paper tries to clarify the status of the market in Social Choice and Individual Values. It shows how Arrow at first intended to propose a third theorem of welfare economics (Feldman [1991]), which would show that the market achieves not only Pareto-optimality, but also equitable social...

Ordered conflict resolution: understanding her tenets cost Keynes his life and Arrow to live under extortionate threat. Now that the Supreme Court of the United States has conquered the Informal Capital Market Cartel’s stranglehold on academic freedom, the literature can now vindicate...

This introduces the symposium on judgment aggregation. The theory of judgment ag­gregation asks how several individuals' judgments on some logically connected propositions can be aggregated into consistent collective judgments. The aim of this intro­duction is to show how ideas from the...

Economic regulation is portrayed as the objective application of clear economic theory to data in order to develop outcomes which overcome the problems associated with natural monopoly in a non-political, unbiased fashion. However, is the appearance of objectivity only skin-deep? This paper...

Judgment aggregation theory generalizes social choice theory by having the aggregation rule bear on judgments of all kinds instead of barely judgments of preference. The paper briefly sums it up, privileging the variant that formalizes judgment by a logical syntax. The theory derives from...

A new class of preference-aggregation rules is proposed, weak-veto rules. Weak-veto rules are applicable in settings characterized by strong pre-existing views on the desirability of different outcomes, whose recommendations should be modified only in the presence of strenuous opposition. They...

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...