How can a particular allocation and prices be implemented? Under what conditions does a policy deliver a unique competitive equilibrium? How many degrees of freedom there are in the determination of the policy variables, or how many are the instruments of policy? In this paper we analyze a...

In this paper we use optimal-instrument and new finite-sample methods to test the empirical relevance of the New Keynesian Phillips curve (NKPC) equation. Unlike generalized method of moments-based methods, these generalized Anderson-Rubin tests are immune to the presence of weak instruments,...

What instruments of monetary policy must be used in order to implement a unique equilibrium? This paper revisits the issues addressed by Poole (1970) and Sargent and Wallace (1975) on the multiplicity of equilibria when policy is conducted with either interest rate or money supply rules. We show...