Migration signatures across the decades: Net migration by age in U.S. counties, 1950-2010

BACKGROUND Migration is the primary population redistribution process in the United States. Selective migration by age, race/ethnic group, and spatial location governs population integration, affects community and economic development, contributes to land use change, and structures service needs. OBJECTIVE Delineate historical net migration patterns by age, race/ethnic, and rural-urban dimensions for United States counties. METHODS Net migration rates by age for all US counties are aggregated from 1950-2010, summarized by rural-urban location and compared to explore differential race/ethnic patterns of age-specific net migration over time. RESULTS We identify distinct age-specific net migration 'signatures' that are consistent over time within county types, but different by rural-urban location and race/ethnic group. There is evidence of moderate population deconcentration and diminished racial segregation between 1990 and 2010. This includes a net outflow of Blacks from large urban core counties to suburban and smaller metropolitan counties, continued Hispanic deconcentration, and a slowdown in White counterurbanization. CONCLUSIONS This paper contributes to a fuller understanding of the complex patterns of migration that have redistributed the U.S. population over the past six decades. It documents the variability in county age-specific net migration patterns both temporally and spatially, as well as the longitudinal consistency in migration signatures among county types and race/ethnic groups.