We dedicate this paper—an extended version of which was previously circulated with the title ''Ambiguity from the Differential Viewpoint''—to Erio Castagnoli on the occasion of his 60th birthday. Abstract The objective of this paper is to show how ambiguity, and a decision maker (DM)'s response to it, can be modelled formally in the context of a general… (More)
The theory of subjective expected utility has been recently extended to allow ambiguity to matter for choice. We propose a notion of absolute ambiguity aversion by building on a notion of comparative ambiguity aversion. We characterize it for a preference model which encompasses some of the most popular models in the literature. We next build on these ideas… (More)
We introduce a general model of static choice under uncertainty, arguably the weakest model achieving a separation of cardinal utility and a unique representation of beliefs. Most of the nonex-pected utility models existing in the literature are special cases of it. Such separation is motivated by the view that tastes are constant, whereas beliefs change… (More)
We introduce and axiomatize dynamic variational preferences, the dynamic version of the variational preferences we axiomatized in , which generalize the multiple priors preferences of Gilboa and Schmeidler , and include the Multiplier Preferences inspired by robust control and first used in macroeconomics by Hansen and Sargent (see ), as well as… (More)
This note provides a behavioral characterization of mutually absolutely continuous multiple priors.