We characterize prior-by-prior Bayesian updating using a model proposed by Gilboa, Maccheroni, Marinacci and Schmeidler (2010) that jointly considers objective and subjective rationality. These rationality concepts are subject to the Bewley unanimity rule and maxmin expected utility,...

We propose a class of multiple-prior representations of preferences under ambiguity where the belief the decision-maker (DM) uses to evaluate an uncertain prospect is the outcome of a game played by two conflicting forces, Pessimism and Optimism. The model does not restrict the sign of the DM's...

Many decision situations involve two or more of the following divergences from subjective expected utility: imprecision of beliefs (or ambiguity), imprecision of tastes (or multi-utility), and state dependence of utility. Examples include multi-attribute decisions under uncertainty, such as some...

This paper extends decision theory under imprecise probabilistic information to dynamic settings. We explore the relationship between the given objective probabilistic information, an agent's subjective multiple priors, and updating. Dynamic consistency implies rectangular sets of priors at the...

The completeness axiom of choice has been questioned for long, and in response, theoretical models of decision making allowing for incomplete preferences have been developed. So far the theoretical accomplishments have however not been paired with empirical evidence on the actual existence of...

Two of the most well known regularities observed in preferences under risk and uncertainty are ambiguity aversion and the Allais paradox. We study the behav- ior of an agent who can display both tendencies simultaneously. We introduce a novel notion of preference for hedging that applies to both...

This paper generalizes the concept of Sequential Equilibrium to allow for ambiguous incomplete information about types or states. We characterize conditions that ensure existence of Sequential Equilibria under ambiguous incomplete information. Under these conditions players form subjective prior...

The problem of how to rationally aggregate probability measures occurs in particular (i) when a group of agents, each holding probabilistic beliefs, needs to rationalise a collective decision on the basis of a single 'aggregate belief system' and (ii) when an individual whose belief system is...

Despite the increasing importance of multiple priors in various domains of economics and the significant theoretical advances concerning them, choice-based incentive-compatible multiple-prior elicitation largely remains an open problem. This paper develops a solution, comprising a...

This paper develops a belief update rule under ambiguity, motivated by the maxim: in the face of new information, retain those conditional beliefs in which you are more confident, and relinquish only those in which you have less confidence. We provide a preference-based axiomatisation, drawing...