東京都心４区における都市再生特別地区とその他都市計画制度の外部効果の比較

 The Act on Special Measures Concerning Urban Renaissance to improve the civic functions and living environment came into force in June 2002 in response to changes in socio-economic situation such as rapid computerization, internationalization, the low birthrate and aging in recent years. The heart of Tokyo's 23 special wards, so called the center core area, where various redevelopment projects have been carried out, is specified as a special area in urban renewal based on this act. On the other hand, under the special ward system, unlike other regions, the authority of urban planning systems and of the development policies has been shared by Tokyo Metropolitan Government and 23 special wards offices. Thus the external effects of the special area in urban renewal and other urban planning systems are expected to differ from other regions and are important in Japanese urban planning.<br> This study aims to measure the external effects by the hedonic approach based on the capitalization hypothesis. The study area involves of Chiyoda, Chuo and Minato ward where developments are actively being carried out towards the Tokyo Olympic and Paralympic in 2020, as well as Taito ward. The study chose the 2015 land prices as the objective variable, and chose land of attributes, such as acreages, front road widths, floor area ratios, as the explanatory valuables, as well as urban planning systems including the special area in urban renewal and zoning designations, and analyzed the overall external effects.<br> First, in order to evaluate the region-specific circumstances, the study examined each ward. Secondly, the total area of the Chiyoda, Chuo and Minato ward was analyzed. Lastly, the four wards including Taito ward where only one the efficient utilization district were analyzed. In the process of the analysis, in order to obtain high coefficients of determination, the study redefined some explanatory values in natural logarithms, such as land prices, distances from the nearest station and the time from the nearest station to Tokyo Station. As a result of the analysis, no urban planning systems showed any effect in Chiyoda word. The efficient utilization district in Chuo ward only showed a high explanatory power, but other significant exploratory valuables were related to the attributes of land. Valuables concerning urban planning systems did not remain in the process of valuables selection. Subsequently, by analyzing all four wards, some explanatory variable that indicates the urban planning systems such as urgent areas in urban renewal, efficient utilization districts and height limitation districts in Minato ward were adopted as the explanatory valuables.<br> By comparison of the predicted land prices given by the model in the article and the real land prices, spatial validity has been confirmed and visualized in detail using GIS. Using the model, the article estimated the external effects of urgent areas for urban renewal under the assumption that Taito word be specified as designated areas. The article adopted three different cases of the designating entire area of Taito ward, the sub-center of metropolitan area and the surrounding areas. The result confirmed a remarkable rise of land prices compared with the real prices.<br> As conclusion, the study confirmed the external effects from urgent areas of urban renewal specified by the cabinet ordinance and Tokyo Metropolitan Government. This fact shows that the designation of special areas of urban renewal has an effect in provincial urban planning policy for Tokyo Metropolis. In addition, efficient utilization districts specified by Chuo ward and height limitation districts specified by Minato ward are also effective on each planning policy. The study also suggested that the external effect of urgent areas of urban renewal specified by Taito word will be high.