Standard type spaces induce belief structures defined by precise beliefs. This paper proposes and analyzes simple procedures for constructing perturbations of such belief structures in which beliefs have a degree of ambiguity. Specifically, we construct ambiguous type spaces whose induced...

The standard model of a Bayesian game used in most applications assumes that players' beliefs are derived from a common knowledge prior on preference parameters. I analyze the robustness of equilibria of such games to perturbations in the information structure. In a type space environment...