Factorial Ecology

Factorial ecology uses factor analysis to analyze social aspects of spatial units that are of theoretical importance to urban ecologists. Factor analysis is a statistical technique that assesses a large number of variables to find a few common underlying dimensions (factors). In the 1960s, with new computing technology and the dissemination of computerized census data, urban ecologists found this technique uniquely suited for statistical assessment of intra- and interurban spatial differentiation. Generally, any research of the 1960s through 1980s that applies factor analysis to the study of sociospatial units is termed factorial ecology.

Beginning with F. L. Sweetser in 1965, early factorial ecology tested theoretical propositions about natural areas of the city. A decade earlier, social area analysis hypothesized that the formation of neighborhood social homogeneity, a concept central to ecology in the Chicago School, is created by three unique social dimensions of an area: socioeconomic status, family status, and race/ethnic status. Factor analytic techniques allowed rigorous statistical evaluation of these dimensions with hundreds of indicators. Factorial ecology ultimately provided partial support for this theory. The method quickly expanded to related areas of substantive interest to urban ecologists.

From the late 1960s through the 1980s, factorial ecology research, especially the work of Brian J. L. Berry and collaborators, provided systematic evaluation of sociospatial differentiation and identification of socioeconomic functional differentiation across cities and regions. Notably, Berry and Rees in 1969 used a factorial approach for evidence that contending theories of land use patterns—concentric zone, sector, multinucleation, and ethnic enclave theories—were based on separate factors that exist alongside one another in many cities. This work led to a theoretical synthesis of land use perspectives. Berry in 1972 used a factorial ecology approach to elucidate latent functional dimensions of the U.S. urban system. Comparative urban analysts adapted factorial ecology to create new classificatory schemes for the study of international urbanization.

Criticisms of factorial ecology studies were numerous but generally part of a larger critique of human ecology, aggregate analysis, and quantitative methods, not critiques of factorial ecology per se. Criticisms included the failure of factorial ecology to incorporate individual volition and subjective interpretation into the modeling process as well as lack of attention to the role of capitalism and cultural context.

Since the 1980s, studies that are explicitly labeled factorial ecology have been rare. However, factor analysis continues to be a widely used method in quantitative spatial analysis, and the identification of underlying social dimensions in space remains a central research issue in urban ecology.