Intercity Migration and Migration Model

Abstract

Some mathematical models have been developed in the area of sociology. These models are classified into gravity models proposed by Stewart, Zipf and Dodd and intervening opportunity (and competing migrant) models proposed by Stouffer. This paper is concerned with the problems of these models in application to the empirical data on the internal migration in our country. In order to research the problems, following two models were tested with the data on intercity migration in Hokkaido prefecture. MI =aX/Ib (intervening opportunity model) MD=cX/Dd (distance model) In the formulas MI and MD are the numbers of migrants from A to B, X is the number of in-migrants between A and B, I is the number of all in. migrants to B, D is the shortest transportation distance from A to B, and a, b, c, d are constants. The test was done by correlation and regression analysis between the observed and expected numbers of migrants presented logarithmicaly from each city of origin to all other cities of destination. The conclusions the test indicated are as follows. The availability of these models is checked by other two factors, namely (1) the factor of direction and (2) the specific push-pull relation between cities. And the effect of distance factor is raised inversely to the population size of the source city. Consequently, migration patterns of cities are classified into next four types. (1) The central city of the prefecture interacts most frequently with each of all other city without the effect of disturbing factor of distance. (2) The data on the cities as secondary center, interacting especially with the cities in specific direction, are not applicable to the models. (3) The data on the cities which interact frequently only with cities of short distance are conformity with the models. Thus, in these cities migrants are powerfully disturbed by distance factor. (4) The data on the cities which interact frequently with cities of the same socio-economic character are not conformed to the models. In comparison of two models, no significant difference concerning availability was found.