(1) About thirty years have passed since the end of the World War II. The Japanese economy recovered from the war ruins with the Korean war as a momentum, and since 1955 has achieved a remarkable growth. In 1972, its GNP reached 298, 700 million in nominal terms, the third largest in the world. Per capita national income, too, increased to 2, 285 which ranked 14th or 15th. Thus Japan has come to be rated as a major economic power.
(2) Such rapid economic growth caused a fierce movement of population from farm areas to big cities. As a result, a phenomenon of excessive density and scarcity has emerged in the nation's distribution of population. And, at the same time, difference in economic expansion has become conspicuous among cities, and in particular the Tokyo Metropolitan area has registered a notable growth.
Also, an increase in the national income and a rise in consumption standards have stimulated development of suburban-central-cities and suburban residential areas. In the course of this development, cities centering around the suburbs have come into existence, In this fashion, the rapid economic growth have had considerable effects on the regional structure of metropolis.
(3) Theories on regional Structure of metropolis were published by the following three Scholars :
(a) The Concentric Zone Hypothesis by E. W. BURGESS
(b) The Sector Theory by H. HOYT
(c) The Multi Nuclei Theory by C. D. HARRIS and E. L. ULLMAN
In the field of geography, R. E. DICKINSON published the Theory of Concentric Circular Zones. Among these, the E. W. BURGESS' Concentric Zone Hypothesis has stood high in the estimation of the academic world.
(4) According to the Concentric Zone Hypothesis, along with growth of a city such phenomena as centralization, specialization and segregation present themselves, and unique zoning develops inside of the city. Then, invasion and succession among these zones bring the result of concentric expansion of a big city. The listed factors to distort the concentric Structure are configuration of the ground, railroads and industries. These factors, however, are considered to be of secondary importance in theory.
But, such concentric growth of a city is far from the actuality in cases of growth of Metropolis in the world. Especially in studying the regional structure of Japanese cities, in my opinion, configuration of the ground and railroads must be taken up as the prime factor. Also, the Sector Theory and the Multi Nuclei Theory should be combined, and the Concentric Zone Hypothesis be attached no more than secondary importance as the theory to valuate the yield of unit area from functions of location.
(5) In this study, both the principle component analysis, a kind of the multivariate analysis, and the cluster analysis are employed. And, 162 cities, wards towns all villages which form the Tokyo metropolitan regions are covered.
The subjects of this study are ever-five-year analyses and changes of the regional structure of the Tokyo Metropolitan Regions since 1955 based on 25 indicators.
(6) A civic-center has been formed under historical and political conditions. Due to advantages of concentration, civic functions have been gathered in a very small area, and from time to time, parts of the functions have been transferred to zones in transition or sub-civic-centers. In this way, a civic center has continued to purify and enhance its civic functions by building of skyscrapers.
On the other hand, the mainstay of civic centers has been shifted to a function of central supervision from the commercial and industrial function which was prominent for the period from 1955 to 1960.
Judging by the component score of the principle component analysis, which indicates the degree of centralization of civic functions, in Tokyo, Chiyoda-ward surpassed Chuo-ward in 1960, and the difference in the degree between the two wards has tended to increase.