Jury Theorems

Dietrich, Franz and Spiekermann, Kai (2016): Jury Theorems.

Abstract

We give a review of jury theorems, including Condorcet's (1785) classic theorem and several later refinements and departures. The review comes with a critique of jury theorems from a social-epistemology perspective. We assess the plausibility of the theorems' conclusions and premises and the potential of jury theorems to serve as formal arguments for the 'wisdom of crowds'. In particular, we argue (i) that there is a fundamental tension between voters' independence and voters' competence, hence between the two premises of typical jury theorems; (ii) that the (asymptotic) conclusion that 'huge groups are infallible', reached by many jury theorems, is an artifact of unjustified premises; and (iii) that the (non-asymptotic) conclusion that 'larger groups are more reliable', also reached by many jury theorems, is not an artifact and should be regarded as the more adequate formal rendition of the 'wisdom of crowds'.

• Item Type: MPRA Paper
• Language: English
• Keywords: jury theorems, Condorcet jury theorem, social epistemology, wisdom of crowds
• Subjects: C - Mathematical and Quantitative Methods > C1 - Econometric and Statistical Methods and Methodology: General > C10 - General; C - Mathematical and Quantitative Methods > C1 - Econometric and Statistical Methods and Methodology: General > C12 - Hypothesis Testing: General; D - Microeconomics > D7 - Analysis of Collective Decision-Making > D70 - General; D - Microeconomics > D7 - Analysis of Collective Decision-Making > D71 - Social Choice ; Clubs ; Committees ; Associations; D - Microeconomics > D7 - Analysis of Collective Decision-Making > D79 - Other; D - Microeconomics > D8 - Information, Knowledge, and Uncertainty > D82 - Asymmetric and Private Information ; Mechanism Design; D - Microeconomics > D8 - Information, Knowledge, and Uncertainty > D83 - Search ; Learning ; Information and Knowledge ; Communication ; Belief ; Unawareness; K - Law and Economics > K0 - General

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