(77.9%). Generally, the percentage of respondents living in their birth regional blocks at the time of the survey is high in metropolitan areas. This is attributable to the plentiful opportunities for higher education and employment near one's home available in these areas, which lessen the need to migrate to other areas for these purposes. It should be noted that the percentage of respondents both born and living in the same blocks at the time of the survey is lower in the Osaka blocks than in the Tokyo and Chukyo blocks. This is considered to be due to a relatively high percentage of people moving to the Tokyo blocks, as shown in the table.

Next, according to Table III-4 (2), the percentage of respondents who live in the birth regional block is particularly high in Shikoku (93.0%), Tohoku (92.8%), and Kyushu/Okinawa (92.8%), while it is low in Tokyo (73.2%), Kita-Kanto (75.3%), and Osaka (75.5%). The percentages of people native to the regional blocks tend to be lower in metropolitan areas and their vicinities. The large population of migrants coming into metropolitan areas from non-metropolitan areas contributes to the relatively low percentages of native population in these areas. The same tendency for decline in the percentages of native population found in the regions in the vicinity of metropolitan areas are considered to be attributable to a certain number of people migrating to those areas with the suburbanization of large metropolitan areas.

A comparison of this survey and the previous survey reveals that the percentages of native-born respondents classified by birth regional block (Table III-4 (1)) significantly increased in Shikoku (+5.7%), Hokkaido (+5.4%) and Chugoku (+3.3%). Meanwhile, the percentages of respondents born in the current residential block (Table III-4 (2)) significantly increased in the Tokyo area (+5.0%) and Chukyo area (+4.0%) and decreased in Kita-Kanto (-8.5%). Among these changes, the values for the Tokyo area, for instance, are considered to have reflected recent trends, which will be explained later. It must be noted, though, that compilation of data categorized into a limited number of survey areas (such as compilation by residential region) tends to be error-prone in general. Caution must be taken when drawing conclusions from limited classifications, especially if distributions vary greatly from survey to survey.

Lastly, the percentages of native population (from the Tokyo block) among respondents currently living in the Tokyo block are shown by age (Figure III-3). The shifts in the percentages as respondents' ages increase show that although the percentage of native population is high at 94.1% for children below 15 years of age, it drops to 76.0% for those aged 20 to 24, recovers to 80% for those aged 25 to 34, but then gradually decreases among the older groups. The percentage falls to 56.6% among people in the first half of their 50s, slightly increase for those in the latter half of their

Figure III-3 Percentage of Native Respondents Among Respondents Living in the Tokyo Area

The result of the 4th Survey excludes “birth place unknown.”

The results of the 5th and the 6th surveys include “sex unknown” but exclude “birth region unknown.”

Tokyo areas include Tokyo, Saitama, Chiba, and Kanagawa.