Temporal and spatial variation in age-specific net migration in the United States

Area of Science:

• Demography
• Population Geography
• Spatial Analysis

Background:

• Fertility differences are decreasing in the United States, making migration a primary driver of population redistribution.
• Understanding migration patterns is crucial for analyzing population changes and regional development.

Purpose of the Study:

• To identify longitudinal trends in age-specific net migration patterns across US counties.
• To determine the extent of spatial clustering in these migration patterns over time.
• To analyze spatiotemporal changes in migration using a neighborhood approach.

Main Methods:

• Utilized newly developed county-level age-specific net migration estimates for the 1990s.
• Supplemented data with longitudinal age-specific migration data from the preceding 40 years.
• Employed spatial autocorrelation analysis to detect geographic clustering of migration.

Main Results:

• Confirmed distinct net migration "signature patterns" for most county types continued into the 1990s.
• Observed temporal variations in the overall volume of migration across five decades.
• Identified persistent, geographically contiguous regions of net in-migration (e.g., Florida, Southwest) and net out-migration (e.g., Great Plains).

Conclusions:

• Longitudinal trends and spatial clustering in age-specific net migration persist.
• Migration patterns exhibit both stability and temporal variation, influenced by geographic "neighborhoods".
• A neighborhood approach is relevant for understanding spatiotemporal migration dynamics.