Theory and Decision

, Volume 61, Issue 4, pp 319–328 | Cite as

Uncommon Priors Require Origin Disputes

  • Robin HansonEmail author


In standard belief models, priors are always common knowledge. This prevents such models from representing agents’ probabilistic beliefs about the origins of their priors. By embedding standard models in a larger standard model, however, pre-priors can describe such beliefs. When an agent’s prior and pre-prior are mutually consistent, he must believe that his prior would only have been different in situations where relevant event chances were different, but that variations in other agents’ priors are otherwise completely unrelated to which events are how likely. Due to this, Bayesians who agree enough about the origins of their priors must have the same priors.


origin common prior disagree Bayesian 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aumann R.J. (1998), Common priors: a reply to Gul. Econometrica 66(4): 929–938CrossRefGoogle Scholar
  2. Gul F. (1998), A comment on Aumann’s Bayesian view. Econometrica 66(4): 923–927CrossRefGoogle Scholar
  3. Morris S. (1995), The common prior assumption in economic theory. Economics and Philosophy 11, 227–253CrossRefGoogle Scholar
  4. Olson J.M., Vernon P.A., Harris J.A., Jang K. (2001), The heritability of attitudes: a study of twins. Journal of Personality and Social Psychology 80(6): 845–860CrossRefGoogle Scholar
  5. Talbott W. (1990), The Reliability of the Cognitive Mechanism: A Mechanist Account of Empirical Justification. Garland Publishing, New YorkGoogle Scholar

Copyright information

© Springer 2006

Authors and Affiliations

  1. 1.George Mason UniversityFairfaxU.S.A.

Personalised recommendations