|
内容記述 |
Recently, the elderly populations of Japan and Western countries have been increasing rapidly. Especially, there has been a remarkable increase in the elderly population of Tokyo in the decade from 1975-1985. However, several characteristics of the aging process are differentiated at the county and township levels, which has considerable significance for the planning and implementation of social service and health care systems. This study probes the spatial distribution of the elderly population of Tokyo, and regional characteristics of the aging process, using one kilometer mesh data from the 1975, 1980 and 1985 Censuses for Tokyo. Specifically, it analyzes the relationship between progression of aging and net effect of population migration for each age group, obtained by cohort survival method. The following is a summary of the results of this analysis: 1) Although Tokyo's population growth for the period of 1970-1985 is stable, the relative and absolute increases in the age groups 65-74 and over 75 has escalated (see Figure 3). The spatial distribution of total population density and of the density of the population over 65, cuts the twenty-three Tokyo wards into zones. The most densely populated zones are located along the Yamanote Railway Loop and other major railway lines. The lower values appear in the metropolitan center, consisting of Chiyoda-ku, Chuo-ku and Minato-ku, and the country area in the western part of Tokyo (see Figures 4 and 5 ) . The rates of the elderly population are identified spatially with two poles: the highest values of over 17.5% appear in the metropolitan center and in the country area. The high meshes have been expanding to cover all of Tokyo City during the 1970-85 period (see Figure 6 ). 2) Location quotients show the relative growth rates of elderly population. Although the high location quotients appear almost exclusively in the country area (see Figure 8 ), the spatial pattern of meshes with location quotients of over 1.0 is complex (see Figure 9 ) . The low location quotients values appear in the suburban area of the Tama Region-notably the meshes of the Tama New Town area are less than 0.0. 3) The growth rates of the elderly population during the 1970-85 period show big differences in spatial distrbution. Thus, the prefecture is divided into five sub-regions: the Metropolitan Center, the Tokyo City excluding the Metropolitan Center, the urban area of the Tama Region, the suburban area of the Tama Region and the country area (see Figure 1 ) . The progressions of aging for each sub-region are accounted for by age-disaggregated net migration rates, estimated by a five-year cohort survival model. Out-migration of the young and aging-in-place of the resident population are responsible for percentage increases for elderly, while in-migration of the non-elderly is the major cause of reductions in elderly concentration (see Figure 15 and Table 1 ). Although the Metropolitan Center has a high elderly population rate, the speed of aging is not high, because of relative decrease of out-migration and unexpected in-migration of population aged 30-64. In the country area, however, though the rate of elderly is also high, out-migration of young people and in-migration of non-elderly population owning dwelling houses, will accelerate the progression of aging. Tokyo City and the urban Tama Region region register relatively low increases in the rates of elderly. In both these sub-regions, in-migration of the young and out-migration of the non-elderly aged 30 and over and 0 -14, are dominant. The in-migrants are from non-metropolitan areas, and the out-migrants correspond to the members of households with young children, leaving these regions for the suburbs. The good balance of the net-migration means that the aging progression of these sub-regions is caused by aging-in-place of the resident population. In the suburban area of the Tama Region, in-migration for all age groups lowers the rate of elderly and reduces the progression of aging for now. However, future progression of aging is expected because of the in-migrants owning houses in this region. |
20024-039-011.pdf (1.2 MB)
