In this research note I propose the use of the undetermined coefficients method as an alternative approach to solve the Central Bank optimization problem in a neo-keynesian economy. The advantage of using this method is that it provides a theory as to how rational expectations are constructed,...

This paper is a study of the history of the transplant of mathematical tools using negative feedback for macroeconomic stabilization policy from 1948 to 1975 and the subsequent break of the use of control for stabilization policy which occurred from 1975 to 1993. New-classical macroeconomists...

We study discretionary equilibria in dynamic linear-quadratic rational expectations models. In contrast to the assumptions that pervade this literature we show that these models do have multiple equilibria in some situations. We demonstrate the existence of multiple discretionary equilibria by...

The standard new Keynesian monetary policy problem is, in its original presentation, a linear model. As a result, only three possibilities are admissible in terms of long term dynamics: the equilibrium may be a stable node, an unstable node or a saddle point. Fixed point stability (a stable...

The new Keynesian monetary policy model studies the response of the inflation – output gap trade-off to policy decisions taken by the Central Bank, concerning the nominal interest rate time trajectory. Under an optimal setup, this model displays a saddle-path stable equilibrium and, if the...

We study the existence and uniqueness properties of monetary policy with limited commitment in LQ RE models. We use a New Keynesian model with debt accumulation in the spirit of Leeper (1991) as a `lab', because this model generates multiple equilibria under pure discretion, and under full...

A minimal central bank credibility, with a non-zero probability of not renegning his commitment ("quasi-commitment"), is a necessary condition for anchoring inflation expectations and stabilizing inflation dynamics. By contrast, a complete lack of credibility, with the certainty that the policy...

This paper is a study of the history of the transplant of mathematical tools using negative feedback for macroeconomic stabilization policy from 1948 to 1975 and the subsequent break of the use of control for stabilization policy which occurred from 1975 to 1993. New-classical macroeconomists...

With non-controllable auto-regressive shocks, the welfare of Ramsey optimal policy is the solution of a single Ricatti equation of a linear quadratic regulator. The existing theory by Hansen and Sargent (2007) refers to an additional Sylvester equation but miss another equation for computing the...

The aim of the present paper is to provide criteria for a central bank of how to choose among different monetary-policy rules when caring about a number of policy targets such as the output gap and expected inflation. Special attention is given to the question if policy instruments are...