Push-Pull Concept

A theory that attempts to identify the motivational factors that drive migration. The concept was introduced by Everett Lee in his article, “ATheory of Migration,” first published in 1966, in which Lee attempted to codify the various considerations that a potential migrant might take into account as a basis for relocation. Lee based his ideas on the earlier work of Ernest Ravenstein, a British geographer who in the late 19th century articulated a series of “laws” of migration. Ravenstein was the first scholar in the industrial age to attempt a systematic study of migratory flows, both within countries and across international boundaries. Ravenstein focused much of his study on the actual movement of people and less on the forces that convinced them to shift location, however, and Lee sought to address the causation of migration. He divided the array of pressures to migrate into two broad categories: those that would “push” an individual or group to migrate, and those that instead would “pull” migrants to a new place. Lee holds that these factors working either alone or in concert, and at various levels of intensity, are responsible for inducing the movement of human beings across space.

The “push” factors that Lee describes are all negative aspects of remaining in the home country that a migrant will seek to avoid and often flee from. Lee did not claim to have produced a complete listing of these, but his compilation contains the majority of common reasons behind the “push” to migrate. These range from life-threatening situations such as famine, threats to one’s life, and natural hazards and disasters, to matters of personal life choices or to seek better economic opportunities, such as finding a suitable spouse or a higher-paying job. 

Other push factors are poor quality of life, especially low standards of housing and medical care, loss of farming opportunities due to desertification (indeed a major cause of migration in the Sahel region of Africa), actual or feared religious and political persecution, and other reasons. Any of these causes and others suggested by Lee are sufficient to convince an individual or group to move to another location, although the friction of distance may prevent migration until a certain threshold of tolerance is exceeded, at which point migration will take place. Push factors by themselves will suffice to instigate a migratory flow, but pull factors also usually play a role in the decision to migrate. These are positive aspects of the target location, whether it is a foreign country or territory, or another place in the country of origin. These include better living conditions, better health care or treatments unavailable in the home country, political or religious freedom, greater opportunities of marrying, etc. Pull factors therefore frequently complement push factors. Some pull factors are related more to amenities; for example, moving to a region that has a more comfortable climate or beautiful scenery (a common factor in the migration of retirees in developed countries). Although rather general, the push-pull concept provides insight into why migration occurs.