A note on viewing functional change in later life as migration

Empirical research on functional decline in later life is expanding our understanding of this aspect of aging. To increase the value of future research it will be necessary to develop more adequate theories of functional transitions. Toward this goal, a conceptual model that views change as mobility between states is proposed. Exploring the analogy between geographic migration and functional change suggests several migration concepts that might be borrowed by aging researchers. These concepts are useful for organizing existing findings, generating new research questions, and identifying the types of data that need to be collected.