Migration regions and population redistribution

"Gross and net migration flows among...[U.S.] states for 1975-80 were used to define migration regions, or groups of states with similar patterns of net interchange. This typology may be characterized as a transition from a northeastern 'core' which lost to all other regions to a northwestern 'periphery' which gained from all other regions. Florida and California were found to have an important role in redistributing population. The typology was also valid for all age groups and across racial and ethnic categories. The typology remained meaningful when the 1975-80 data were compared to 1965-70 and 1980-85 data, despite great volatility in net migration and significant change in the placement of many states." Data are taken primarily from the 1980 census.