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...

This paper shows that increased volatility of Örm-level productivity can push the nominal interest rate to its lower bound with large amplification effects on macroeconomic aggregates. The framework combines a simple canonical Önancial accelerator model, time varying risk shocks, and a zero...