Journal of Risk and Uncertainty

, Volume 35, Issue 2, pp 107–127 | Cite as

Whom should we believe? Aggregation of heterogeneous beliefs

  • Christian Gollier


We examine the collective risk attitude of a group with heterogeneous beliefs. We prove that the wealth-dependent probability distribution used by the representative agent is biased in favor of the beliefs of the more risk tolerant consumers. Moreover, increasing disagreement on the state probability raises the state probability of the representative agent. It implies that when most disagreements are concentrated in the tails of the distribution, the perceived collective risk is magnified. This can help to solve the equity premium puzzle. We show that the trade volume and the equity premium are positively correlated.


Aggregation of beliefs State-dependent utility Efficient risk sharing Disagreement Asset pricing Portfolio choices 

JEL Classification

D81 D83 


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Toulouse School of Economics (LERNA, EIF and IDEI)ToulouseFrance

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