How common are common priors?
AbstractTo answer the question in the title we vary agentsʼ beliefs against the background of a fixed knowledge space, that is, a state space with a partition for each agent. Beliefs are the posterior probabilities of agents, which we call type profiles. We then ask what is the topological size of the set of consistent type profiles, those that are derived from a common prior (or a common improper prior in the case of an infinite state space). The answer depends on what we term the tightness of the partition profile. A partition profile is tight if in some state it is common knowledge that any increase of any single agentʼs knowledge results in an increase in common knowledge. We show that for partition profiles that are tight the set of consistent type profiles is topologically large, while for partition profiles that are not tight this set is topologically small.
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Bibliographic InfoArticle provided by Elsevier in its journal Games and Economic Behavior.
Volume (Year): 74 (2012)
Issue (Month): 2 ()
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Web page: http://www.elsevier.com/locate/inca/622836
Common prior; Common knowledge; Knowledge; Belief;
Other versions of this item:
- D82 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Asymmetric and Private Information; Mechanism Design
- D83 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Search, Learning, and Information
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- Yaw Nyarko, 2010. "Most games violate the common priors doctrine," International Journal of Economic Theory, The International Society for Economic Theory, vol. 6(1), pages 189-194.
- Faruk Gul, 1998. "A Comment on Aumann's Bayesian View," Econometrica, Econometric Society, vol. 66(4), pages 923-928, July.
- Nyarko, Yaw, 1991. "Most Games Violate the Harsanyi Doctrine," Working Papers 91-39, C.V. Starr Center for Applied Economics, New York University.
- R. Aumann, 2010.
"Correlated Equilibrium as an expression of Bayesian Rationality,"
513, UCLA Department of Economics.
- Aumann, Robert J, 1987. "Correlated Equilibrium as an Expression of Bayesian Rationality," Econometrica, Econometric Society, vol. 55(1), pages 1-18, January.
- Robert J. Aumann, 2010. "Correlated Equilibrium as an expression of Bayesian Rationality," Levine's Working Paper Archive 661465000000000377, David K. Levine.
- John C. Harsanyi, 1967. "Games with Incomplete Information Played by "Bayesian" Players, I-III Part I. The Basic Model," Management Science, INFORMS, vol. 14(3), pages 159-182, November.
- Robert J. Aumann, 1998. "Common Priors: A Reply to Gul," Econometrica, Econometric Society, vol. 66(4), pages 929-938, July.
- Rodrigues-Neto, José Alvaro, 2009. "From posteriors to priors via cycles," Journal of Economic Theory, Elsevier, vol. 144(2), pages 876-883, March.
- Samet, Dov, 1998. "Iterated Expectations and Common Priors," Games and Economic Behavior, Elsevier, vol. 24(1-2), pages 131-141, July.
- Martin Hellwig, 2011.
"From Posteriors to Priors via Cycles: An Addendum,"
Working Paper Series of the Max Planck Institute for Research on Collective Goods
2011_07, Max Planck Institute for Research on Collective Goods.
- Andrea Collevecchio & Marco LiCalzi, 2011.
"The probability of nontrivial common knowledge,"
6, Department of Management, Università Ca' Foscari Venezia, revised Mar 2012.
- Ziv Hellman, 2012.
"Countable Spaces and Common Priors,"
Discussion Paper Series
dp604, The Center for the Study of Rationality, Hebrew University, Jerusalem.
- Hellman, Ziv, 2013. "Weakly rational expectations," Journal of Mathematical Economics, Elsevier, vol. 49(6), pages 496-500.
- Jose Alvaro Rodrigues-Neto, 2011.
"The Cycles Approach,"
ANU Working Papers in Economics and Econometrics
2011-547, Australian National University, College of Business and Economics, School of Economics.
- Ziv Hellman, 2010.
"Almost Common Priors,"
Discussion Paper Series
dp560, The Center for the Study of Rationality, Hebrew University, Jerusalem.
- Martin Hellwig, 2011. "Incomplete-Information Models of Large Economies with Anonymity: Existence and Uniqueness of Common Priors," Working Paper Series of the Max Planck Institute for Research on Collective Goods 2011_08, Max Planck Institute for Research on Collective Goods.
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