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 un-certainty. 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.
equity premium puzzle model misspecification Natural rate of interest risk-free rate puzzle robust control