Duality of Housing Demand and Supply with Mixed Concentration and Diffusion: Case Study of Takasaki City Facing an Era of Depopulation

The duality of housing demand and supply with mixed concentration and diffusion is studied in Takasaki city, which is located in the northern Kanto plain. Takasaki is classified as a core city (one of the major cities in the Kanto region). In 2014, the Act on Special Measures concerning Urban Regeneration was revised in order to address Japan's declining population. To maintain a certain population density and rebuild the hub-and-spoke urban structure, Takasaki city government formulated its own location normalization plan, the Compact Plus Network, in 2020. At the center of Takasaki, in addition to business and commercial functions, the city government is actively attracting residential functions, such as high-rise condominiums. Together with the transition to a society having a declining population, there is a growing drive toward a pedestrian-oriented city that does not depend on private cars for daily life. The population of central Takasaki doubled from1995 to 2020. The survey conducted for this study indicates that condominiums in downtown Takasaki are sold at higher prices than detached houses in the suburbs, so it can be presumed that the income levels of downtown residents are higher than those of suburban residents. According to the national census, many downtown residents are office workers who moved in from outside Gunma Prefecture, and a high percentage of them work outside the prefecture. If downtown residents commute by Shinkansen (bullet train), their commuting time to central Tokyo would be about 60 minutes. Therefore, taking into account the convenience of a Shinkansen commute, it is reasonable to consider that downtown residents would purchase condominiums within walking distance of Takasaki station. In contrast, in the suburbs, the supply of detached houses is booming. Land that had been used for agricultural purposes is being developed for residential purposes. However, housing supplied in the suburbs, unlike that supplied in the downtown area, is less convenient for public transportation such as buses and trains. The census shows that many suburban residents are workers in manufacturing industries who moved from Takasaki, and a high proportion of them work in and around it. Therefore, their means of commuting is exclusively by private car. Originally, manufacturing industries, including factories, were located in the suburbs of Takasaki. This forms the main place of employment for these workers. Among suburban housing with poor access to public transportation, detached houses are being built after removing older houses. Furthermore, new houses are also being built on agricultural or waste land that had never been used for housing. Detached houses are being built on land with a high risk of flooding, such as pre-improved channels and floodplains. This is a matter of concern, taking into account the rate of frequent natural disasters, such as typhoons and earthquakes, in recent years.