Hierarchically organized migration fields: the application of higher order factor analysis to population migration tables.

"The structure of human geographical systems is often of a hierarchical nature. Population migration systems can usefully be conceptualized as a series of hierarchically related levels of migration fields: the fields at one level nesting within the fields at the next higher level. Such migration fields and the relationships between different levels can be extracted from large population migration origin-destination matrices with the aid of higher order factor analysis." A case study of the western United States illustrating the application of higher order factor analysis to large interaction matrices is presented. excerpt