Using variables derived from several conceptualizations of the environment, this study assesses the predictability of of fiscal (as measured by per capita property tax revenue) among 21 municipal governments at two points in time. The data bear out the notion that it is useful to consider revenue level as a funcion of social variables differing in time and space. The results also suggest that current views of environmental impact on municipal government make the system excessively static. Findings indicate that over time one can expect marked changes in the influence of various environmental features. A central feature of the alleged urban crisis is the fiscal dilemma faced by municipal governments. Dwindling revenues seem to threaten their abilities to meet the service expectations of their populations. They are simultaneously pressed for increased municipal services, and for reducing, or at the very least, stabilizing the of taxation to be borne by constituents. These two issues-a demand for higher services, combined with tax rates perceived as excessive-have become of paramount importance in local and state elections and are beginning to emerge as issues in national politics. These problems stem from the declining ability of municipal government to mobilize fiscal support' from its traditional source, the local property tax. This tax has been the mainstay of municipal fiscal systems. Not all municipalities have experienced this set of problems to the same extent and some have avoided them altogether. The question then arises: What factors can be used to explain these differing experiences? The present investigation hypothesizes that differences in the abilities of municipal governments to mobilize the fiscal of its citizenry are, in large part, a function of the patterns of environmental differentiation within which political systems must function. There is a substantial literature demonstrating the fruitfulness of conceptualizing governmental behavior as a response pattern to environmental variation. Easton (1953; 1965a; 1965b) presents a treatment of the theoretical position 1 The dependent variable is conceived, in this article, as one aspect of the functioning of local governments within a specifiable, but complex, environment. The concept of is taken from the theoretical work of the political scientist David Easton (1953; 1965a; 1965b). Oran R. Young (1968) points out that in the Easton paradigm the concept of is a means of describing one set of relationships to the political system on the part of constituents. For the purposes of the present inquiry support mobilization levels are seen as the at which a municipal government can obtain revenues from its property tax in order to establish or to maintain certain of governmental service activity. The of attained by any given municipality is a system characteristic that includes both resources and pressures for performance, demand, in Easton's terms. An alternative type of analysis of government fiscal performance would be a traditional economic treatment of supply and demand for specific outputs. For the purposes of sociological or political analysis, where the purpose is to obtain information about holistic system properties of local governments, a more generalized conception of system output, such as is more appropriate. At this level of analysis it is very difficult to obtain pure measures of either supply or demand. Indeed, supply and demand factors are empirically fused in the system's environment, as are the absolute and relative aspects of these factors (i.e., the proportion of wealthy individuals in a community is related to the system's objective resources, to specific services demanded, to generalized conceptions of the desirability of high of service, and to willingness to be taxed).