It is clear that both voluntary and involuntary forces normally contribute to the residential segregation existing between groups. For the most part, the contribution of each dimension has not been determined. Rather, researchers operate as if either one or the other force is operating. In the United States, for example, black-white segregation is assumed to be imposed by whites on blacks, as if the latter were themselves totally indifferent to the racial composition in their areas of residence. On the other hand, it is assumed that segregation between white ethnic groups is at present purely a voluntary matter. In an earlier period, it was assumed that their segregation was both voluntary (reflecting desires to be among compatriots) and involuntary (reflecting the imposition of restrictions on residential movement by other groups as well as economic forces). But it has not been possible for investigators to determine the relative importance of each factor. Using asymmetrical segregation indexes, a rudimentary procedure is proposed for determining the relative importance of voluntary and involuntary forces operating to generate a given level of segregation. Data based on Black, Anglo, and Spanish residential patterns are then considered in terms of the proposed model.