Hostname: page-component-5d59c44645-7l5rh Total loading time: 0 Render date: 2024-02-22T20:14:00.561Z Has data issue: false hasContentIssue false

Deliberation with Evidence

Published online by Cambridge University Press:  25 August 2011

University of Toulouse
Jérôme Mathis is Assistant Professor, Toulouse School of Economics, University of Toulouse 1 Capitole, Manufacture des Tabacs, Aile Jean-Jacques Laffont, F219, 21, Allée de Brienne, F-31000 Toulouse, France (


In committee deliberation, requiring a unanimous vote intuitively provides the strongest incentives for actors to share fully their opinions and private information. It is also believed that full revelation of (decision-relevant) information occurs when personal biases are made clear before deliberation. However, recent literature suggests that both intuitions are flawed. Austen-Smith and Feddersen propose a model in which the unanimity rule performs worse than other rules in promoting fully revealing deliberation, and uncertainty about individuals' preferences promotes full sharing of information. We extend this work by incorporating the possibility that individuals may provide verifiable evidence for their private information. Under this circumstance, we demonstrate that Austen-Smith and Feddersen's results are reversed. First, a unanimous voting rule performs better than any other, as unanimity is the only rule that always promotes fully revealing deliberation. Second, under fairly general conditions, uncertainty about individuals' preferences prevents full sharing of information.

Research Article
Copyright © American Political Science Association 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)



Austen-Smith, D., and Feddersen, T.. 2005. “Deliberation and Voting Rules.” In Social Choice and Strategic Decisions: Essays in Honor of Jeffrey S. Banks, ed. by Austen-Smith, David and Duggan, John. Heidelberg, Germany: Springer-Verlag.Google Scholar
Austen-Smith, D., and Feddersen, T.. 2006. “Deliberation, Preference Uncertainty, and Voting Rules.” American Political Science Review 100 (2): 209–17.Google Scholar
Bade, S. and Rice, A.. 2007. “Political Advocacy with Collective Decision Making.” Pennsylvaia State University. Working Paper.Google Scholar
Bohman, J. and Rehg, W.. 1997. “Deliberative Democracy: Essays on Reason and Politics.” Cambridge, MA: MIT Press.Google Scholar
Coughlan, P. J. 2000. “In Defense of Unanimous Jury Verdicts: Mistrials, Communication, and Strategic Voting.” American Political Science Review 94: 375–93.Google Scholar
Doraszelski, U., Gerardi, D., and Squintani, F.. 2003. “Communication and Voting with Double-sided Information.” Contributions to Theoretical Economics 3 (1): Article 6.Google Scholar
Dryzek, J. and List, C.. 2002. “Social Choice Theory and Deliberative Democracy: A Reconciliation.” British Journal of Political Science 3 (1): 128.Google Scholar
Elster, J. 2000. Deliberative Democracy. Cambridge: Cambridge University Press.Google Scholar
Eriksen, E. 2001. “Governance or Democracy? The White Paper on European Governance.” Symposium: Mountain or Molehill? A Critical Appraisal of the Commission White Paper on Governance, Jean Monnet Center, New York University.Google Scholar
Gerardi, D. and Yariv, L.. 2007. “Deliberative Voting.” Journal of Economic Theory 134: 317–38.Google Scholar
Giovannoni, F. and Seidmann, D. J.. 2007. “Secrecy, Two-sided Bias and the Value of Evidence.” Games and Economic Behavior 59: 296315.Google Scholar
Grossman, S. J. and Hart, O. D.. 1980. “Disclosure Laws and Takeover Bids.” Journal of Finance 35: 323–34.Google Scholar
Levy, G. 2007. “Decision Making in Committees: Transparency, Reputation and Voting Rules.” American Economic Review 97 (1): 150–68.Google Scholar
Mathis, J. 2008. “Full Revelation of Information in Sender–Receiver Games of Persuasion.” Journal of Economic Theory 143: 571–84.Google Scholar
Milgrom, P. and Roberts, J.. 1986. “Relying on the Information of Interested Parties.” Rand Journal of Economics 17: 1832.Google Scholar
Meirowitz, A. 2006. “Designing Institutions to Aggregate Private Beliefs and Values.” Quarterly Journal of Political Science 1 (4): 373–92.Google Scholar
Meirowitz, A. 2007. “In Defence of Exclusionary Deliberation: Communicating and Voting with Private Beliefs and Values.” Journal of Theoretical Politics 19: 301–28.Google Scholar
Milgrom, P. 1981. “Good News and Bad News: Representation Theorems and Applications.” Bell Journal of Economics 12: 380–91.Google Scholar
Schulte, E. 2010. “Information Aggregation and Preference Heterogeneity in Committees.” Theory and Decision 69: 97118.Google Scholar
Seidmann, D. J. and Winter, E.. 1997. “Strategic Information Transmission with Verifiable Messages.” Econometrica 65: 163–70.Google Scholar
Shapiro, I. 2002. “Optimal Deliberation.” Journal of Political Philosophy 10: 116.Google Scholar
Visser, B. and Swank, O. H.. 2007. “On Committees of Experts.” Quarterly Journal of Economics 122: 337–72.Google Scholar
Walker, J. and Lane, D.. 1994. “The Jury System.” Victorian Council for Civil Liberties Discussion Paper (25 February 1994).Google Scholar