قوانین نرخ بهره معین قیمت و ارزش پول در یک جهان غیر ریکاردویی

This article studies under which conditions interest rate rules “à la Taylor” [1993. Discretion versus policy rules in practice. Carnegie–Rochester Conference Series on Public Policy 39, 195–214] lead to price determinacy. We scrutinize notably two famous results, which are standard in the traditional “Ricardian” model with a single dynasty of consumers: (1) a pure interest rate peg leads to nominal price indeterminacy; (2) a strong reaction (usually more than one for one) of nominal interest rates to inflation is conducive to price determinacy (the Taylor principle). This article extends the analysis to rigorous dynamic non-Ricardian models. The results turn out to be quite different, since notably prices may be determinate if the interest rate responds less than one for one to inflation, and even under a pure interest rate peg.

Following Taylor’s (1993) seminal article, there has been recently a very strong renewal of interest in the study of interest rate rules for monetary authorities (for a survey of recent work, see for example McCallum, 1999; Taylor, 1999). In line with the recent trends in macroeconomics, several authors quite naturally investigated interest rate policies in rigorous dynamic general equilibrium models. Most rigorous studies of optimal interest rate rules in such a maximizing framework have been cast in “Ricardian” economies populated with a single dynasty of consumers.1 These economies have, however, as far as policy analysis is concerned, a number of particular properties, and it thus seems legitimate, in line with the intuition first developed in Bénassy (2000), to extend the analysis of interest rate rules to non-Ricardian economies where new agents enter in each period, and to see whether this makes a difference or not for the analysis. We shall see that it does.

We have seen that going from a Ricardian to a non-Ricardian framework changes dramatically the conditions for price determinacy under interest rate rules. It is usually found in a Ricardian framework that interest rate pegging leads to nominal indeterminacy, and that a more than one to one response of interest rates to inflation leads to price determinacy.