CONSTRAINED GRAVITY MODEl (DISTRIBUTION MODEL) THE GREAT MIGRATION
The Great Migration, a long term movement of African Americans from the South to the urban North transformed many northern cities between 1916 and 1970. Chicago was one of those cities, who attracted slightly more than 500,000 of the approximately seven million African Americans who left the South during these decades in search of job opportunities and better lifestyle (Grossman 2005). This phenomena of the Great Migration can be explained with the help of ‘Constrained Gravity Model’ which is used in social science field of study. The Gravity model is derived from the Newton’s ‘Laws of Gravitation’ in physics. The model predicts the level of interaction in movement of population, volume of traffic or number of telephone calls between the two study areas provided one knows the population of the study areas and the distance between them. Whereas, the Constrained Gravity Model takes into consideration relative functional distance that influences destination choices instead of the absolute physical distance. This distribution model predicts the pattern of region to region interactions (Hartshorn 1996).
African Americans constituted just 2 percent of Chicago’s population before the Great Migration, but by 1970, it was increased to 33 percent. This population which was marginal at one point of time in Chicago emerged by the mid-twentieth century as a powerful force in the city’s political, economic and cultural life. Although the migration of African Americans had been contributing to Chicago’s black community since the 1840s, the city offered few job opportunities to this group until World War I. During World War I, when there was a halt in immigration from Europe at that time Chicago’s employers were in need of new source of labor which was then filled by this group of African American migrants from south. When the news of new jobs opportunity was spread through the Chicago Defender newspaper, many black southerners going to other northern cities were attracted to Chicago. Equally important were the correspondence and visits that established “migration chains,” linking Chicago with numerous southern communities, especially in Mississippi (Grossman 2005).
During World War II, in 1940s and 1950s this migration got accelerated rapidly with the expansion of industry in Chicago. But by 1960s, many industries like packinghouses got closed and steel mills started declining this resulted in the degeneration of hard work labor jobs and the city had opportunities mainly for educated men and women. By 1980s, there was a reverse migration of African American class of people from Chicago, especially retired people began to return back to their respective homeland (Grossman 2005).
In this event taking into consideration the Constrained Gravity Model, Mississippian formed the stronger ties with Chicago as compared to the other southern areas. On the other hand, it can be assumed that Chicago attracted more southerners as compared to other northern cities may be because it is geography-wise centrally located and thus was easily approachable. In this particular case, ‘Constrained Gravity Model’ works more aptly because Chicago had job opportunities which acted as a migrant demands and the African Americans acted as a migrant suppliers, thus balancing the distribution.
African Americans constituted just 2 percent of Chicago’s population before the Great Migration, but by 1970, it was increased to 33 percent. This population which was marginal at one point of time in Chicago emerged by the mid-twentieth century as a powerful force in the city’s political, economic and cultural life. Although the migration of African Americans had been contributing to Chicago’s black community since the 1840s, the city offered few job opportunities to this group until World War I. During World War I, when there was a halt in immigration from Europe at that time Chicago’s employers were in need of new source of labor which was then filled by this group of African American migrants from south. When the news of new jobs opportunity was spread through the Chicago Defender newspaper, many black southerners going to other northern cities were attracted to Chicago. Equally important were the correspondence and visits that established “migration chains,” linking Chicago with numerous southern communities, especially in Mississippi (Grossman 2005).
During World War II, in 1940s and 1950s this migration got accelerated rapidly with the expansion of industry in Chicago. But by 1960s, many industries like packinghouses got closed and steel mills started declining this resulted in the degeneration of hard work labor jobs and the city had opportunities mainly for educated men and women. By 1980s, there was a reverse migration of African American class of people from Chicago, especially retired people began to return back to their respective homeland (Grossman 2005).
In this event taking into consideration the Constrained Gravity Model, Mississippian formed the stronger ties with Chicago as compared to the other southern areas. On the other hand, it can be assumed that Chicago attracted more southerners as compared to other northern cities may be because it is geography-wise centrally located and thus was easily approachable. In this particular case, ‘Constrained Gravity Model’ works more aptly because Chicago had job opportunities which acted as a migrant demands and the African Americans acted as a migrant suppliers, thus balancing the distribution.