In this study, social mobility of the labor force in four urban areas, two in Canada and two in the United States, is researched. Based on data provided by a questionnaire, four components of social mobility are analyzed: (1) structural change patterns of occupational mobility; (2) social origins of nonmigrants; (3) intergenerational mobility; and (4) correlation of locality to social mobility. The impact of social origins and personal resources is assessed and the dependence relationships between diverse social structures and the mobility achieved within them is described. A city type comparison indicates the relative socioeconomic attainment predictable in various social settings. A lengthy bibliography and sample questionnaire are appended. (Author/WI)