Shrinkage of regional cities in Japan: Analysis of changes in densely inhabited districts

摘要

City populations are shrinking all over the world, and this subject has gained attention in recent years. In Japan, policies for addressing population decline in regional areas have focused on prefectural capitals. This study analyzes the relationships between the densely inhabited districts (DIDs) of central cities (prefectural capitals) and the DIDs of their surrounding areas from 1960 to 2015, in regional areas of Japan. Population changes between a central city's DID and its surrounding DIDs were classified into four categories according to the developmental processes involved. The results suggest that the demographic development process of central city and surrounding DIDs is related to the concentration of population and industry in the central city. In addition, the population decline of central city DIDs is caused by a combination of factors such as a decrease in the population of young people, outflow of business establishments from the central city, and social decline resulting from the outflow of residents and formation of residential areas outside central city DIDs.