Model Misspecification, the Equilibrium Natural Interest Rate and the Equity Premium

This paper analyses the determinants of the natural rate of interest in a non-linear model where agents are uncertain over both future technology growth and the future course of monetary policy. I show that the real natural rate can be affected by sizable uncertainty premia, including premia associated with monetary uncertainty. This result is potentially problematic for both the estimation of the natural rate and its use as a policy indicator. Monetary uncertainty can also contribute to amplify the equity premium, and to account for its apparent, positive link with inflation