Christian List

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers new to the field of judgment aggregation a sense of this rapidly growing research area.

This chapter explores the relationship between Goldman's thesis and the classical jury theorem. It identifies the minimal modification needed in order to recover Goldman's thesis in a Condorcetian framework. Goldman's thesis can be recast as a generalization of the classical Condorcet jury theorem. The central move needed to recover Goldman's thesis from a generalized jury theorem is to replace Condorcet's assumption that there is a single truth to be tracked with the assumption of multiple such truths: one for each voter. In Goldman's picture, there is still an indirect, derivative sense in which there exists an 'overall' truth about the correct outcome for the electorate in aggregate. This 'overall' truth is determined, of course, by the profile of voter‐specific truths and therefore depends on the identity of the electorate. The chapter also provides some numerical examples to illustrate the implications of the generalized jury theorem.

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers new to the field of judgment aggregation a sense of this rapidly growing research area.

Deliberation and Decision explores ways of bridging the gap between two rival approaches to theorizing about democratic institutions: constitutional economics on the one hand and deliberative democracy on the other. The two approaches offer very different accounts of the functioning and legitimacy of democratic institutions. Although both highlight the importance of democratic consent, their accounts of such consent could hardly be more different. Constitutional economics models individuals as self-interested rational utility maximizers and uses economic efficiency criteria such as incentive compatibility for evaluating institutions. Deliberative democracy models individuals as communicating subjects capable of engaging in democratic discourse. The two approaches are disjointed not only in terms of their assumptions and methodology but also in terms of the communication - or lack thereof - between their respective communities of researchers. This book provides a comprehensive overview of the recent debate between the two approaches and makes new and original contributions to that debate.