Shrinkage Does Not Follow Population Decline on a Regional Scale: Planning and Reality of Residential Area in Japan

This study first examines changes in the amount of residential area on a regional scale, which is said to shrink following population decline, using Japan as an example, where population decline is already underway in most of the country. Second, it examines how the regional governments have set future targets for residential areas and whether these targets are consistent with the current trend. Third, it examines how prefectures, Japan’s regional governments, are responding to this situation through regional land use planning. The methodologies of the paper are a combination of collecting and sorting out the related data, reviewing and extracting information from planning documents, and conducting interviews with persons in charge. In conclusion, residential areas have continued to increase on a regional scale, even as the population has declined. Shrinkage does not follow population decline on a regional scale. It was also found that the amount of residential area changed more closely with the change in households than with the population. National and regional land use plans generally set targets for more shrinkage than the actual trend. The underestimation of the amount of residential area was due to the rapid decline in the number of persons per household. Cases of the three prefectures showed that specific control is left to the individual acts, while the measures are indicated in the wording by the prefectural land use plans.