Studies of migration regions are characterized by two separate conceptual approaches. The first views migration regions as clusters of highly interconnected spatial units (subsystems) while the other defines them as groups of spatial units with a similar geographic structure of flows (typologies). This paper highlights the theoretical and methodological distinctions between migration subsystems and typologies. An empirical analysis using U.S. migration data for 1940, 1960, and 1980 shows that although migration subsystems and typologies have both changed over time, each reveals a different dynamic of regional change and has different morphological characteristics.
Notes
∗The data used in this study were obtained under NSF Grant SES-8911064. I wish to thank Brigitte Waldorf for comments on an earlier draft of this paper and Wendy Shaw for research assistance. Maps were prepared by Xue Ling Hu of the UGA Cartographic Services.