Testimony before the Senate Subcommittee on Migratory Labor. It reviews why rural people move to urban areas; effects on migrants; effects on origin and destination. (1) Demographic and economic imbalances underlying migration include high rural natural increase and mechanization of agriculture. (2) Migration improves living standards and employment opportunities, notably for disadvantaged groups like blacks. So far as subjective adjustment is measurable, most migrants believe they are better off after moving to urban areas. (3) Migrants are, economically, more like urbanites joined than rural residents left. Although not a net gain when they first arrive, migrants soon become indistinguishable from native urban population of same education, age, race, and sex. Policy recommendations: (1) strengthen effectiveness of rural out-migration as means of individual material improvement, and (2) retain viability of declining areas as alternatives to urban living by consolidating delivery of health, education, and other social services. 20 pp.