This paper proposes a model of decision under ambiguity deemed vector expected utility, or VEU. In this model, an uncertain prospect, or Savage act, is assessed according to (a) a baseline expected-utility evaluation, and (b) an adjustment that reflects the individual’s perception of ambiguity...

In Anscombe and Aumann’s (1963) domain, there are two types of mixtures. One is an ex-ante mixture, or a lottery on acts. The other is an ex-post mixture, or a state-wise mixture of acts. These two mixtures have been assumed to be indifferent under the Reversal of Order axiom. However, we...

The standard framework for analyzing games with incomplete information models players as if they form beliefs about their opponents' beliefs about their opponents' beliefs and so on, that is, as if players have an infinite depth of reasoning. This strong assumption has nontrivial implications,...

I study a dynamic principal agent model in which the effort cost of the agent is unknown to the principal. The principal is ambiguity averse, and designs a contract which is robust to the worst case effort cost process. Ambiguity divides the contract into two regions. After sufficiently high...

We study preferences for timing of resolution of objective uncertainty in a menuchoice model with two stages of information arrival. We characterize a general class of utility representations called hidden action representations, which interpret an intrinsic preference for timing of resolution...