We study type spaces where a player's type at a state is a conditional probability on the space. We axiomatize these spaces using conditional belief operators, examining three additional axioms of increasing strength. First, introspection, which requires the agent to be unconditionally certain...

This paper investigates the extent to which rationalizable implementation depends on the implicit common knowledge restrictions usually embodied in traditional models. It is shown that under fairly general conditions such restrictions are without loss of generality in the following sense: If a...