تنوع محصولات، طعم ناهمگن، توزیع فعالیت های اقتصادی جغرافیایی :تعاملات بازار در مقابل تعاملات غیربازاری

There are two independent strands of literature on the geographic distribution of economic activities. One is the new economic geography that emphasizes product diversity, and the other is probabilistic migration that stresses taste heterogeneity in residential location. This article incorporates these two characteristics into a single framework, and analyzes how they affect the number and stability of equilibrium geographic structures. It shows that the home market effect due to market-mediated product diversity creates an agglomeration force, whereas idiosyncratic taste differences due to non-market interactions serve as a probabilistic immobile factor and induce a dispersion force. The tension between these opposite forces, together with the decline in transportation costs, yields different patterns of agglomeration and the associated changes in interregional wage differentials.

The interregional differences in economic activities arise from myriad market and nonmarket interactions. This view dates back at least to Hicks [14]. In “The Theory ofWages” Hicks proposed that the persistence of regional differences in wages is due to “differences in the cost of living” and “indirect attractions of living in certain localities.”1 Thirty years later, Sjaastad [35] divided the costs and returns of migration into “money” and “nonmoney” factors. The money costs are literally pecuniary ones, whereas the non-money costs are subdivided in two: “opportunity costs” related to the distance of migration and the level of unemployment in the destination, and “psychic costs” that prevent people from leaving familiar surroundings, family, and friends.

Based on the theoretical underpinning of new economic geography and probabilistic migration, this article reincorporates bothmarket and non-market interactions into a unified framework in the spirit of Hicks, Jacobs, and Sjaastad. It shows that market-mediated product diversity yields an agglomeration force through the home market effect, whereas taste heterogeneity due to non-market interactions serves as a “probabilistic immobile factor” and induces a dispersion force.