Theory of Intervening Opportunities by S.A. Stouffer

Samuel A. Stouffer gave the theory of intervening opportunities in his work “Intervening Opportunities: A Theory Relating Mobility and Distance” in 1940. This theory shows that the nature of geographic space is more important than the distance in determining migration behavior. According to Ravenstein’s Laws, distance is the most important factor in determining the migration composition and volume. However, Stouffer’s intervening opportunities model presents a more deep understanding of the process of migration.

Basic Postulations

  • Stouffer’s model is a hybrid of the Gravity Model of Migration. Instead of selecting the size of cities, Stouffer uses the number of opportunities as a pulling force.
  • He states that the magnitude of migration is directly proportional to the number of opportunities available at place of origin and destination.
  • Additionally, it is inversely proportional to the number of intervening opportunities available between the two places.

Let’s Disaggregate Stouffer’s Theory

The above postulations give a basic idea about the operation of this theory in the real world. Let us disaggregate this theory.

  • In Stouffer’s model, the opportunities  act as pulling forces and barriers or problems act as push forces. The magnitude of migration depends on the sum of push and pull forces at place of origin as well as destination.
  • The place offering more opportunities has greater pull and becomes the destination. Contrarily, the place where the opportunities are limited becomes the place of origin.
  • Therefore, greater the difference in number of opportunities available at both these places, greater the migration.
  • Additionally, the availability of opportunities between place of origin and destination intercepts the flow of migration. Hence, many of the migrants stop at the intervening cities and do not proceed to the large city.

    Fig. 1: Intervening Opportunities Model
  • In Fig. 1, we can see that City-B has more opportunities (+) than the City-A. Additionally, City-A has more disadvantages (-) than City-B. Hence, the net flow of migration will be from City-A towards the City-B.
  • Sometimes, the intervening opportunities outweigh pull factors at City-B. Hence, not all the migrants originating from City-A reach the City-B because of the intervening opportunities in City-C. Some of the migrants are able to fulfil their purpose of migration in City-C, so, they do not proceed further away from their birthplace or hometown.

    Equation 1: Formulae for  Intervening Opportunities Model
  • Above all, the purpose of migration determines if the person will stop in the middle or proceed to the final destination.
  • For instance, if a person wants to find employment and City-C can provide it to him, he will not proceed to City-B.
  • Equation 1 shows the formulae for calculating the net immigration to City-B.

Modification by Stouffer

Equation 2: Modified Intervening Opportunities Model Formulae
  • Stouffer realized that the migration does not solely depend on opportunities at place of origin and destination.
  • Magnitude of migration also depends on competition among migrants from different regions. For example, a lot of students want to take admission in the college of Delhi but the competition among students is very high. Therefore, only few among the millions clear the entrance exam and get admission in Delhi while the rest of students migrate to other cities for education. Similarly, if many workers are applying for few jobs in a city, then most workers will avoid that city.
  • The formulae for estimation for net migration to City-B is as shown in Equation 2.

Conclusion and Relevance

Stouffer’s model of migration was a novel approach for addressing the volume and direction of migration. It is a positivist model and used the gravity model to estimate migration between two places. Since, it considers the intervening space is an important part of the process of migration, it becomes very practical. This model explains the volume and direction of migration with 90 percent accuracy. Despite the quantitative vigor of this model, it lacks the behavioral and sociological parameters which play very large role in migration composition. For instance, a uneducated and unaware people are likely to stay in their birthplace. Thereafter, Lee presented his ideas in the Model of Intervening Obstacles which provide comprehensive explanation about volume, direction and composition of migration streams.