Abstract
This paper suggests that the formulation and testing of hypotheses relating the functional role of cities in a society to other urban structure and process variables might be facilitated by substituting a continuous variable approach to the functional system for the prevailing discrete typologies. Using variables indexing the scope of economic activities in U.S. communities at two points in time, we elaborate a technique for identifying the dimensions underlying an existing typology, and the 56 largest SMSA’s are ranked along these dimensions.