Monotone Continuous Multiple Priors.

We show that the monotone continuity condition introduced by Villegas (1964) and Arrow (1970) is the behavioral counterpart of countable additivity (and relative weak compactness) in a multiple priors model. This generalizes their original result, in which the special case of a singleton set of priors is considered. Further extending their results, we provide a behavioral counterpart for the convex rangedness of the priors (both considered singularly and as a vector measure).