Social area analysis essentially involves a statistical procedure to identify from a sometimes quite large database of socio-economic data the most salient underlying variables. Very often most of the variance in a group of dozens of variables can be accounted for by three or four dimensions.
It is probably fair to say that the heyday of this approach occurred in the 1970s. It has cropped up frequently in scholarly literature in the years since, but there seems to have been only a modest amount of new theoretical work in this area. Social area analysis and factorial ecology have also been quite important in marketing research.
See, for example, Carl-Gunnar Janson, “Factorial social ecology: an attempt at summary and evaluation,” Annual Review of Sociology, 1980, vol. 6, pp. 433-456 (JSTOR link).