We study the optimal monetary policy problem in a New Keynesian economy with a zero lower bound (ZLB) on the nominal interest rate, when the steady state natural rate (r*) becomes permanently negative. We show that the optimal policy aims to approach gradually a new steady state with positive...

cover -- Contents -- Series Foreword -- Preface -- Introduction -- A Simple Model of Unemployment and Inflation Dynamics -- Unemployment, the Output Gap, and the Welfare Costs of Economic Fluctuations -- Unemployment and Monetary Policy Design in the New Keynesian Model -- Concluding Remarks and...