The Wisdom of the Multitude: Diversity Versus Size

Part of the Logic, Argumentation & Reasoning book series (LARI, volume 14)


The Condorcet Jury Theorem (CJT), together with a large and growing literature of ancillary results, suggests two conclusions regarding collective wisdom. First, large committees outperform small committees, other things equal. Second, heterogeneous committees can, under the right circumstances, outperform homogeneous ones, again other things equal. But this literature has done little to bring these two conclusions together. This paper employs simulations to compare the respective contributions of size and difference to optimal committee performance. It demonstrates that the contributions depend dramatically upon bias. In the presence of low bias, committee composition matters little. In the presence of high bias, it can matter a great deal; optimal committee performance, however, does not vary dramatically between low- and high-bias committees.


Bias Collective wisdom Condorcet Jury Theorem Diversity Monte Carlo simulations 



Earlier versions of this paper were presented at the 6th Munich-Sydney-Tilburg Conference on Models and Decisions, Munich, April 10–12, 2013, and at the 3rd Annual Conference of the European Political Science Association, Barcelona, June 20–22, 2013. We would like to thank participants at both events for helpful comments and suggestions.


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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.Department of Political ScienceTrinity College DublinDublinIreland
  2. 2.Faculty of EconomicsOsaka University of EconomicsOsakaJapan

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