Population Suburbanization in American Metropolitan Areas, 1940–1970

Using census tract data, this paper shows that massive changes have occurred in density patterns of American metropolitan areas since 1950. Suburbanization of population has involved both large-scale decongestion of central parts of metropolitan areas and also large-scale outward deconcentration. Many metropolitan areas no longer have clearly distinguishable density patterns in their central and peripheral parts. At the present time, patterns of population distribution across metropolitan areas are becoming increasingly similar. Furthermore, current suburbanization patterns by census tract do not relate strongly to suburbanization patterns as measured by growth rates of crude central city and suburban rings in metropolitan areas. Finally, the paper shows that “density craters” in the center of many metropolitan areas may become more pronounced, although they may not extend outward.