Dispersed Spatial Price Equilibrium

Abstract

The concept of a spatial price equilibrium has dominated the network-based models of spatial competition ever since Samuelson's (1952) formulation of this concept as a mathematical program. In practice, however, this model has often been a poor predictor of interregional flows and regional commodity prices. In this paper an extension of the spatial price equilibrium model is presented, in which attempts are made to overcome the poor predictive capabilities of this model by imbedding it within a gravity model representation of interregional flows. After the conceptual framework of this model is stated, a variational inequality formulation is presented and this formulation is then used to derive a convex mathematical programming statement of this model. Solution algorithms and sensitivity analysis of the equilibrium solution are discussed, and in the conclusion to the paper a discussion of the extensions of this model are presented which incorporate multiple commodities and imperfect competition in the regional commodity markets.