Tastes, Singular and Regular Economies : The Negishi Point of Vew and the Gaussian Curvature

Standard decision theory encodes preferences as a complete, transitivepreorder predefined in a set of alternatives.In this paper we consider changes in preferences in pure exchange economies.We will analyze the repercussions of these changes on the economic structure,particularly on the set of Walrasian equilibria available for an economy.The set of Pareto efficient allocations can change if preferences change, even whenthe available resources do not change, and consequently the set of Walrasian equilibriacan change as result of changes in preferences with important repercussions on the economic welfare.We will introduce a metric to define proximity between economies whose consumers have modifiedtheir preferences and we will analyze the stability of the economies underdisturbances in preferences according wit this metric.We will introduce the definition of Gaussiancurvature of an economy to analyze the stability of the preferences. Finally we show the relationship between the Gaussian curvature an regular economies for two different definitions of such economies