Optimal Robust Monetary Policy with Parameters and Output Gap Uncertainty

Abstract

This paper studies optimal robust monetary policy when the central bank imperfectly observes potential output and has Knightian uncertainty about the intertemporal elasticity of substitution and the slope of the Phillips curve. The literature on optimal robust monetary policy has focused on either imperfect observability of some variables or on parameter uncertainty. We characterize robust monetary policy analytically under the two types of uncertainty and show that in general they call for a more aggressive reaction of monetary policy compared with the certainty case.