We consider a principal-agent model with moral hazard where the agent's knowledge about the performance measure is ambiguous and he is averse towards ambiguity. We show that the principal may optimally provide no incentives or contract only on a subset of all informative performance measures....

We develop a theory of optimal stopping problems under ambiguity in continuous time. Using results from (backward) stochastic calculus, we characterize the value function as the smallest (nonlinear) supermartingale dominating the payoff process. For Markovian models, we derive an adjusted...

Properties of dynamic stochastic general equilibrium models can be revealed by either using numerical solutions or qualitative analysis. Very precise and intuition-building results are obtained by working with models which provide closed-form solutions. Closed-form solutions are known for a...