In a Markov decision problem with hidden state variables, a posterior distribution serves as a state variable and Bayes' law under an approximating model gives its law of motion. A decision maker expresses fear that his model is misspecified by surrounding it with a set of alternatives that are...

This paper studies the design of optimal time-consistent monetary policy in an economy where the planner trusts its own model, while a representative household uses a set of alternative probability distributions governing the evolution of the exogenous state of the economy. In such environments,...

Central banks face uncertainty about the true location of the effective lower bound (ELB) on nominal interest rates. We model optimal discretionary monetary policy during a liquidity trap when the central bank designs policy that is robust with respect to the location of the ELB. If the central...