We study environments with sticky prices, wages or portfolios where it is feasible and optimal to use monetary policy to replicate the allocation under full flexibility. In these environments the optimal policy does not depend on the scope of the frictions. In this sense, the strength of the...

What instruments of monetary policy must be used in order to implement a unique equilibrium? This paper revisits the issues addressed by Sargent and Wallace (1975) on the multiplicity of equilibria when policy isconducted with interest rate rules. We show that the appropriate interestrate...

We consider standard cash-in-advance monetary models and show that there are interest rate or money supply rules such that equilibria are unique. The existence of these single instrument rules depends on whether the economy has an infinite horizon or an arbitrarily large but finite horizon.

We consider a standard cash in advance monetary model with flexible prices or prices set in advance and show that there are interest rate or money supply rules such that equilibria are unique. The existence of these single instrument rules depends on whether the economy has an infinite horizon...

It is believed that a shock, common to a set of countries with identical fundamentals, has identical outcomes across countries. We show that in general, when specialization in production is such that a common shock creates a missing role for labor mobility across countries, the terms of trade of...

We show that short and long nominal interest rates are independent monetary policy instruments. The pegging of both helps solving the problem of multiplicity that arises when only short rates are used as the instrument of policy. A peg of the nominal returns on assets of different maturities is...

We derive principles of optimal short run monetary policy in a real business cycles model, with money and with monopolistic firms that set prices one period in advance. The only distortionary policy instruments are the nominal interest rates and the money supplies. In this environment it is...

This paper assesses the relevance of the exchange rate regime for stabilization policy. This regime question cannot be dealt with independently of other institutions, in particular how .fiscal policy is designed. We show that once .fiscal policy is taken into account, the exchange rate regime is...