Abstract
This paper examines whether the levels of neighborhood segregation by household income in small areas had increased since the late 1990s and explores the background to income segregation. First, we proposed a small area estimation method for income distribution and compared the household income distribution in Ota ward in Tokyo in 2003 and in 1998. Second, the relationship between residential mobility and income level in small areas was investigated.
Income distribution was estimated using individual data from a housing demand survey in conjunction with small area census data. The estimated results revealed that overall household income had fallen over those 5 years and that the variation in income among households had widened. In addition, an increase in the dissimilarity index implied that spatial segregation by household income had increased. It appears that neighborhood segregation by income was accompanied by residential differentiation by housing and family type. The level of segregation, however, was not significantly high when compared with that in other cities overseas referred to in previous studies.
From an analysis of intraurban mobility using data from telephone directories, an association between the income level of residents' origin-destination districts and the increasing number of households moving to wealthy or poor areas was found. These results indicate that local immigration had contributed to neighborhood segregation by household income. On the other hand, a large population inflow could lead to geographic diversity with regard to household income in several districts in Ota ward under the influence of postindustrialization.
