We offer a theory of polarization as an optimal response to ambiguity. Suppose individual A's beliefs first-order stochastically dominate individual B's. They observe a common signal. They exhibit polarization if A's posterior dominates her prior and B's prior dominates her posterior. Given...

Dynamic consistency leads to Bayesian updating under expected utility. We ask what it implies for the updating of more general preferences. In this paper, we characterize dynamically consistent update rules for preference models satisfying ambiguity aversion. This characterization extends to...

When do dynamic nonconvexities at the disaggregate level translate into dynamic nonconvexities at the aggregate level? We address this question in a framework where the production of differentiated intermediate inputs is subject to dynamic nonconvexities and show that the answer depends on the...

We consider a model where agents work in sequence on a project, share information not available to the principal, and can collude. Due to limited liability the Coase theormem does not apply. The distribution of surplus among the agents is there an important control variable for the principal,...

We consider the problem of inducing agents who are concerned with their careers to reveal their private information about a project which has originated with one of them. A successful project raises the inventor's chance of promotion, at his peer's expense. Thus, the peer has an incentive to...

We use a simple graphical moral hazard model to compare monitored (non-traded) bank loans versus traded (non-monitored) bonds as sources of external funds for industry. We contrast the conditions that theoretically favour each system, such as the size and number of firms, with conditions...