THE literature on urban structure and function indicates that the workplaces of labor force members are spatially separated from their residences, in part because of the differentiated pattern of urban land use. There is also some evidence of appreciable variation in the degree of workresidence separation among different component groups of the labor force.' On the basis of previous studies, it may be expected that two of the major determinants of the degree of work-residence separation are the socio-economic level of the worker and the centralization of the workplace. It is hypothesized (1) that the degree of workresidence separation varies directly with the socio-economic level of the worker, (2) that the degree of separation is directly related to the centralization of the workplace, and (3) that the degree of separation is greatest for workers of high socio-economic level with centralized workplaces. Although the relationships between socioeconomic level, centralization of workplace, and degree of work-residence separation may obtain as hypothesized for the total labor force, they may be modified or reversed for particular subgroups. effects of other demographic and economic factors, including color, sex, and duration of employment with the present establishment, on the relationships are examined. Data. data which the study analyzes were obtained as a by-product of the Occupational Mobility Survey, conducted in January and February of 1951 in Chicago.2 A systematic sample of approximately 2,000 households was drawn from the city, and work history schedules were completed for each person twenty-five years or older in the sample households who worked full-time for pay or in his own business for a month or more during 1950. schedule number permitted identification of the census tract of residence. Information on color, sex, income, occupation, family status, and duration of employment was obtained directly from the schedules. All identifying information on current workplace was examined. schedule provided no identifying information on workplace for self-employed persons; hence, they are excluded from this analysis. In most cases, the industry group and the name of the employing firm were available for wage and salary workers. addresses of the employing establishments were located through telephone directories or published firm listings and assigned to census tracts by means of a street address coding guide. For assignment of a workplace location, it was necessary that there be a single determinable workplace. Cases for which no workplace could be assigned are of two types: * Revision of a paper read at a meeting of the Society for Social Research of the University of Chicago, June, 1953. This research was supported in part by the U. S. Air Force under Contract Number AF 33 (038)-25630, monitored by the Human Resources Research Institute. Permission is granted for reproduction, translation, publication and disposal in whole and in part by or for the U. S. Government. 1J. Douglas Carroll, Jr., Some Aspects of the Home-Work Relationships of Industrial Workers, Land Economics, 25 (November, 1949), pp. 413-22; Carroll, The Relation of Homes to Work Places and the Spatial Pattern of Social Forces, 30 (March, 1952), pp. 271-82; Helene M. Conant, The Locational Influence of Place of Work on Place of Residence, M.A. thesis, University of Chicago, March, 1952; Otis Dudley Duncan and Beverly Davis, Nos. 5, 13, 20 in the unpublished series of Urban Analysis Reports, Chicago Community Inventory, University of Chicago, 1951-53; Kate K. Liepmann, Journey to Work, New York: Oxford University Press, 1944, Part B, Chapter II; Leo F. Schnore, The Separation of Home and Work: A Problem for Human Ecology, Social Forces, 32 (May, 1954), pp. 336-43. 2 For a summary of the entire Occupational Mobility Survey, see Gladys L. Palmer, Labor Mobility in Six Cities, New York: Social Science Research Council, 1954. transfer of the information from the original schedules for Chicago workers to a card form suitable for an analysis of work-residence separation was planned and supervised by Evelyn M. Kitagawa.