Changing Residence in the City: A Review of Intraurban Mobility

BOUT 20 percent of the population of the United States changes residence annually. Although many moves are made by a small number of highly mobile persons, 50 percent of the entire population moves within a five-year period. Given the extent of this movement, the distribution and characteristics of the population remain remarkably stable; the in-migrants to an area, for the most part, resemble the out-migrants in numbers and attributes. Over a sufficient period of time, however, migration is an important instrument in altering the spatial patterns of social and demographic variables, and under certain conditions it leads to dramatic short-run changes in small areas-for example, the rapid growth of a new subdivision or the expansion of a ghetto by blockbusting. The present study is concerned with an important, but relatively neglected, aspect of migration, namely changes in residence that take place within a city.' Measured in one-year intervals, the intracounty mobility rate is 12 to 13 percent, or about two-thirds of all moves (Table I).2 Many of these relocations take place in the same neighborhood or on the same block, but longer moves determine most of the growth or decline of population in different parts of the city and virtually all the changes in relative income levels and ethnic or racial concentrations.