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Judgment Aggregation Theory

In collaboration with Christian List, I study how a collective can form judgments on interconnected propositions, based on the judgments of its members. For instance, how can an expert panel assess whether global warming is accelerating, whether an acceleration would increase worldwide inequality, and whether inequality reduction should be a policy goal? Collective judgments should be at the same time logically coherent and democratically responsive to individual judgments — a double objective that is hard to meet. The question of the right procedure is wide open. Judgment aggregation has many applications and attracts interest from various disciplines, such as economics, philosophy, political science, jurisprudence, artificial intelligence, and logic.

Related Work

• Judgment Aggregation (with C. List), book under review at Cambridge University Press
• Dynamically rational judgment aggregation (with C. List), Social Choice and Welfare, forthcoming
• Categorical versus graded beliefs, Frontiers in Psychology 18: 817940, 2022
• The relation between degrees of belief and binary beliefs: a general impossibility theorem (with C. List). In: I. Douven (ed.) Lotteries, Knowledge, and Rational Belief. Essays on the Lottery Paradox, Cambridge University Press, 2021, pp. 223-54
• From degrees of belief to binary beliefs: Lessons from judgment-aggregation theory (with C. List), Journal of Philosophy 115: 225-270, 2018 → Official Version
• Introduction to the special issue 'Beliefs in Groups' of Theory and Decision (with W. Rabinowicz), Theory and Decision 85: 1-4, 2018 → Official Version
• Probabilistic opinion pooling generalized. Part one: general agendas (with C. List), Social Choice and Welfare 48: 747-786, 2017 → Official Version
• Probabilistic opinion pooling generalized. Part two: the premise-based approach (with C. List), Social Choice and Welfare 48: 787-814, 2017 → Official Version
• Judgment aggregation and agenda manipulation [fully rewritten with additional results], Games and Economic Behavior 95: 113-36, 2016 → Official Version
• Aggregation theory and the relevance of some issues to others [fully rewritten!], Journal of Economic Theory 160: 463-493, 2015 → Official Version
  • For a few additional results see the 2006 version (Meteor Research Memorandum RM/07/002, Maastricht University, 2007)
• Aggregating causal judgments (with R. Bradley and C. List), Philosophy of Science 81(4): 491-515, 2014 → Official Version
• Judgment aggregation in search for the truth (with I. Bozbay and H. Peters), Games and Economic Behavior 87: 571-590, 2014 → Official Version
• Scoring rules for judgment aggregation, Social Choice and Welfare 42(4): 873-911, 2014 → Official Version
• Judgment aggregation and the discursive dilemma, in: Encyclopedia of Philosophy and the Social Sciences, edited by Byron Kaldis, SAGE Publishing, 2013
• Propositionwise judgment aggregation: the general case (with C. List), Social Choice and Welfare 40: 1067-1095, 2013 → Official Version
• Towards a unified theory of aggregation (with C. List), Social Choice and Welfare Prize Lecture, SCW Meeting, 2010
• The possibility of judgment aggregation on agendas with subjunctive implications, Journal of Economic Theory 145(2): 603-638, 2010 → Official Version
• The aggregation of propositional attitudes: towards a general theory (with C. List), Oxford Studies in Epistemology 3: 215-234, 2010 [Corrigendum]
• Majority voting on restricted domains (with C. List), Journal of Economic Theory 145(2): 512-543, 2010 → Official Version
• Un bilan interprétatif de la théorie de l'agrégation logique (with P. Mongin as first author), Revue d'Economie Politique 120: 929-72, 2010 → Official Version
• The premise-based approach to judgment aggregation (with P. Mongin), Journal of Economic Theory 145(2): 562-582, 2010 → Official Version
  • An earlier version which results about infinite populations
• The impossibility of unbiased judgment aggregation (with C. List), Theory and Decision 68: 281-299, 2010 → Official Version
• The problem of constrained judgment aggregation (with C. List). In: F. Stadler et al. (eds.), The Present Situation in the Philosophy of Science, Berlin: Springer, 2009 → Official Version
• A liberal paradox for judgment aggregation (with C. List), Social Choice and Welfare 31(1): 59-78, 2008 → Official Version
• Judgment aggregation without full rationality (with C. List), Social Choice and Welfare 31(1): 15-39, 2008 → Official Version
• Judgment aggregation under constraints (with C. List), in Economics, Rational Choice and Normative Philosophy, T. Boylan and R. Gekker (eds.), London (Routledge), 2008 → Official Version
• Strategy-proof judgment aggregation (with C. List), Economics and Philosophy 23: 269-300, 2007 → Official Version
• Judgment aggregation by quota rules: majority voting generalized (with C. List), Journal of Theoretical Politics 19(4): 391-424, 2007 → Official Version
• Arrow's theorem in judgment aggregation (with C. List), Social Choice and Welfare 29(1): 19-33, 2007 → Official Version
• A generalised model of judgment aggregation (earlier title: "Judgment aggregation in general logics"), Social Choice and Welfare 28(4): 529-565, 2007 → Official Version
• Judgment aggregation with consistency alone (with C. List), unpublished, 2007
• Judgment aggregation: (im)possibility theorems, Journal of Economic Theory 126(1): 286-298, 2006 → Official Version
• Judgment aggregation without full rationality: a summary (with C. List), Proceedings of the 1st International Workshop on Computational Social Choice (COMSOC), Amsterdam, 2006, pp. 139-152

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