Shocks en modelos dinámicos bajo previsión perfecta:un análisis del corto plazo.

Abstract

The object of this paper is to analyze the comparative dynamic properties of a non-sthocastic dynamic model with two differential equations under perfect foresight. Since the equilibrium of the model exhibits saddle-point stabilitv, we are able to explore rigorously (without bringing in agents' optimizing behaviour) a move to a new equilibrium through the unique convergence path. The model is based on Blanchard (1981), though this author only presents a diagrammatic study without refering to the methemetical solutions. In this sense, this paper presents in a thorough manner, a formal resolution inherent in this model; the analysis extends its epplicability to all kind of dynamic models with simultaneous equations under perfect foresight. We analyze the effects of monetary or fiscal shocks (unanticipated and permanent, anticipated and permanent, unanticipated and transitory and anticipated and transitory) and establish rigorously the set of hypothesis on which the analysis of the shocks is based. As a consequence of the mathemetical analysis, one of the main conclusions obtained, is that the economy will always, or almost always, be very close to the equilibriun point.