Ecology of urban socialchange—An American example

The recent literature of urban social ecology has produced an emergent body of theory and methodology together with empirical verification. Yet, the entire conception is dependent upon cross-sectional analyses or international comparisons, with little attention directed to processes of change. This paper focuses explicitly on system change by comparing cross sections over time and by the direct decomposition of change data. The first approach, which has been extensively utilized, should provide evidence consistent with existing theory. The second approach, which is less well understood, should provide an alternative set of perspectives.

Empirical content is provided by analyzing a consistent 43 variable set for the census tracts of Detroit both for 1960 and 1970. In addition, the same variable set is constructed to represent change over the decade and then analyzed for the identification of change dimensions. For both time periods theoretically expected dimensions emerge. However, the substantive simplicity of the 1960 structure is far more complex a decade later. Much of the additional complexity involves the separation of family status related variables from a unidimensional concept to an increasingly multidimensional representation. It is suggested that these findings are not unique and they may represent the emergence of post-industrial patterns. Although cross-sectional findings and change dimensions derived from change variables are related, they are not the same. These two approaches provide differing perspectives on the nature of urban system modification.