Inflation targets and contracts with uncertain central banker preferences

Within a standard model of monetary delegation we show that the optimal linear inflation contract performs strictly better than the optimal inflation target when there is uncertainty about the central banker's preferences. The optimal combination of a contract and a target performs best and eliminates the inflation bias and any variability not associated with supply shocks. However, variability due to shocks is enhanced by uncertain central banker preferences. Quadratic contracts are shown to overcome this problem partly, but the advantages of delegation may still be dominated by the "excess variability" due to shocks. Hence, the credibility-stabilization trade-off is restored.