手法を比較

	Intervening Opportunities Model	Push-Pull Factor Analysis
分野	Migration Studies	Migration Studies
系統	Regression model	Process / pipeline
提唱年	1940	1966
提唱者	Samuel A. Stouffer	Everett S. Lee
種類	Spatial-interaction model of migration volume	Conceptual decomposition framework for migration determinants
原典	Stouffer, S. A. (1940). Intervening Opportunities: A Theory Relating Mobility and Distance. American Sociological Review, 5(6), 845-867.	Lee, E. S. (1966). A Theory of Migration. Demography, 3(1), 47-57.
別名	Stouffer Intervening Opportunities, Opportunity-Based Migration Model, Law of Intervening Opportunities	Push and Pull Framework, Lee's Migration Framework, Origin-Destination Factor Analysis, Plus-Minus Factor Model of Migration
関連	3	3
概要	The intervening opportunities model, introduced by Samuel Stouffer in 1940, explains the volume of migration between two places not by the physical distance separating them but by the number of opportunities available at the destination relative to the opportunities a migrant would encounter along the way. Its central claim is provocative: there is no necessary relationship between mobility and distance. Distance only matters because crossing more of it usually means passing more chances to stop. Formally, the number of people moving a given distance is directly proportional to the number of opportunities at that distance and inversely proportional to the number of intervening opportunities. Stouffer revised the model in 1960 to add 'competing migrants' — rivals converging on the same destination from other origins — giving spatial-interaction analysis an alternative to the gravity model that is grounded in opportunity structure rather than mass and distance.	Push-pull factor analysis is the framework, formalized by Everett Lee in his 1966 article 'A Theory of Migration,' that decomposes every migration decision into four classes of force: factors at the area of origin that repel, factors at the area of destination that attract, a set of intervening obstacles between the two, and personal factors specific to the migrant. Lee argued that each place carries a mix of pluses, minuses, and zeros whose valence differs from person to person, and that migration occurs when the net balance of these forces, discounted by the obstacles and filtered by individual circumstance, favors moving. The framework's enduring appeal is that it organizes the bewildering variety of migration causes into a single comparative logic of origin versus destination. Massey and colleagues' 1993 review placed push-pull within the broader landscape of migration theory, noting both its descriptive power and its lack of a deeper behavioral mechanism. In empirical practice the framework is operationalized by comparing measurable attributes of origin and destination areas and relating their differentials to observed flows. It remains the default conceptual scaffolding for organizing migration determinants in policy and applied research.