【摘要】Economists have long been interested in explaining urban spatial structure, i.e., the location and density of residential and nonresidential activity in urban areas and their spatial linkages. Because of the widespread availability of information on the level of population by geographic subareas for large numbers of cities at different points in time, much of their attention has focused on population density gradients, that is, the functional relationship between population density and distance from the center of the city. Cohn Clark provided the first systematic empirical analysis of these density gradients and suggested the use of the negative exponential function to describe the decline in population densities with distance from the urban center.? Numerous authors have attempted to provide theoretical explanations of these empirical regularities, and Edwin Mills and Richard Muth have both made some effort to use density functions to test their models of urban spatial structure.

【文献来源】Jr D H, Kain J F. Journal of Urban Economics, 1974, 1(1):61-98.