Abstract
In Japan, the phenomenon of the concentration of population into cities is one of the most serious problems. Laws off migration by Ravenstein, E.G. have still gotten a footing in investigation into the national-wide migration with special reference to cities. Quantitative analyses have been applied to his findings since by many investigators. The present writer aims at understanding the characteristics and regularities of the recent migration by applying for the first time the following two statistical techiniques: coefficient of evenness derived from the Lorenz curve calculated on prefecture level (abridged as coefficient of evenness) and the coefficient of correlation (γ) between moving-in and moving-out population. The purpose of this study is to deal with this phenomenon from the viewpoint of population geography. The main object of the study is the moving-in and -out population in large cities, and, for comparison, the transference of population in all prefectures is of the secondary concern. The years of 1959 and 1966 were chosen for the calculation, and the attention was paid also to the changes in population during the period between 1959 and 1966.
The results are as follows:
i) In 1959, the coefficients of evenness of the moving-in population in the six large cities are respectively 0.493 for the ward areas of Tokyo, 0.388 for Osaka-city, 0.375 for Kyoto-city, 0.304 for Nagoya-city, 0.296 for Kobe-city and 0.291 for Yokohama-city. In 1966, the coefficients in the seven large cities are 0.497 for the ward area of Tokyo, 0.406 for Kyoto-city, 0.369 for Osaka-city, 0.349 for Nagoya-city, 0.304 for Yokohama-city, 0.298 for Kobe-city, and 0.219 for Kitakyushu-city. Since the coefficients of evenness of the moving-in population in large cities correspond to the population capacity of cities, the coefficients may safely become a parameter of measuring the levels of centrality in large cities. In case the coefficients of which cities the coefficients of evenness the moving-in population in the year of 1959 is above 0.300 and that of 1966 is above 0.340 in a given city, it may be fitly regarded as the national centre, and those in which the coefficients were below the values mentioned above the regional or local centre, the ward area of Tokyo, Osaka-city, Nagoya-city and Kyoto-city come under the category of the national centre, while Yokohama-city and Kobe-city fall into the category of the regional centre. In the case of Kitakyushu-city in 1966, it may be classified as the local centre, as the coefficient of evenness was extremely small. The differences in the coefficients of evenness of the moving-out population among the large cities are relatively small, as compared with those of the moving-in population, and the range of the former is less than one-third of the latter. It is simply because of the common tendencies of the large cities that were caused by the transfer of residential sites from the cities: the move-out of dwellers in the urban centre to the short-distance areas is striking in the large cities. By these reasons mentioned above, the coefficient of evenness of the moving-out population is not applicable for a measurement of centrality in large cities.
ii) The average distances of the moving-in population into the six large cities, in 1959, were 286 km in the ward area of Tokyo, 225 km in Kobe-city, 243 km in Nagoya-city, 223 km in Osaka-city, 207 km in Yokohama-city and 201 km in Kyoto-city, and the grand average distance of these cities was 261 km. In 1966, the average distances of the moving-in population into the seven large cities were 309 km in Kitakyushu-city, 292 km in the ward area of Tokyo, 271 km in Nagoya-city, 242 km in Kobe-city, 239 km in Osaka-city, 231 km in Yokohama-city and 214 km in Kyoto-city. The grand average distance of the six large cities, excluding Kitakyushu-city, was 269 km, longer by 8 km than that of 1959.
