Group Beliefs

We extend the frameworks of Harsanyi (1967) and Mertens and Zamir (1985) to study the higher-order beliefs that groups of individuals obtain by pooling their information. A universal group type space is constructed, which contains all of the belief hierarchies that could be held by any group of players in any type space. This formalism is used to study group belief invariant Bayes correlated equilibria; this is shown to be the minimal solution concept that only depends on group belief hierarchies and contains all Bayes Nash equilibria.