Learning, robust monetray policy and the merit of precaution

We study in a New Keynesian framework the consequences of adaptative learning for the design of robust monetary policy. Compared to rational expectations, the fact that private follows adaptative learning gives the central bank an additional intertemporal trade-off between optimal behavior thanks to ability to manipulate future inflation expectations. We show that adaptative learning imposes a more restrictive constraint on monetary policy robustness to ensure the dynamic stability of the equilibrium than under rational expectations and weakens the argument in favor of a more aggressive monetary policy when the central bank takes account of model misspecifications.