Oligopolistic competition and optimal monetary policy

This paper studies optimal monetary policy in a DSGE model with supply side strategic complementarity, as arising from oligopolistic competition, and nominal rigidities. Firms' oligopolistic rents induce inefficient fluctuations through both, intra-temporal and intertemporal time-varying wedges. Optimality requires the use of state contingent inflation taxes to smooth and reduce firms' rents. Hence, under optimal (Ramsey) policy PPI deviates significantly from zero. A comparison of welfare costs for a set of operational rules relatively to the Ramsey plan shows that targeting the output gap, the mark-up and the asset price improves upon a rule with aggressive response to inflation.