Attempts to determine the role of migration into Illinois as a possible explanation for the rapidly increasing demand for public assistance in the Chicago metropolitan area. The study compares migrant and native welfare recipients, utilizing data from 1967 to 1971 to estimate the effect of in-migration on Chicago's welfare caseload. These findings emerged: Although a substantial proportion of the households receiving welfare in Chicago are migrants, relatively few migrant families received assistance within the first year after moving to the state. Most migrants receiving aid under the Aid to Dependent Children program had resided in the state at least five years. Although family caseloads increased threefold, the migrant-native ratio remained relatively constant during the period examined. In sum, there is little evidence to support the view that low-income families moving to Chicago recently are a principal cause of the city's rapidly growing family caseload. (See also R-1387, R-1389.) 28 pp.