Definition and Measurement of Residential Segregation
According to Massey and Denton (1988), residential segregation “is the degree to which two or more groups live separately from one another, in different parts of the urban environment”(282). Now this is a pretty general definition, but it gives basic but good insight as to what residential desegregation is talking about. In this paper, I will mostly be focusing on residential segregation as it relates to the black and white populations in relation to one another, although I will be referencing some other races briefly to create a better understanding of concepts or ideas.
At a deeper level, residential segregation has five different dimensions to it that it is measured by, those are: evenness, exposure, concentration, centralization, and clustering. All of these different dimensions are measure in different ways, but the most common measurement of residential segregation is done with the dissimilarity index, or the DI. The dissimilarity index “is a measure of the evenness with which two groups are distributed across the component geographic areas that make up a larger areas” (Racial Residential Segregation). As I underlined, the dissimilarity index is one way to measure the dimension of evenness for residential segregation. A DI measurement can range from a measurement of zero to one- hundred. Leah Platt Boustan gives and example of how this index works in her article Racial Residential Segregation In American Cities, “consider a city with a population that is half black and half white and that is divided into two neighborhoods. In the least segregated distribution of the population, each neighborhood would itself be half black and half white, reflecting the city average (DI=0). In the most segregated distribution, the first neighborhood would me entirely black and the second neighborhood would be entirely white (DI=100)” (Boustan, p. 1). As far as it goes for what is considered highly segregated measurements and lower segregated measurements, cities with a measurement under 30 is considered well integrated, cities with a measurement between 30 and 60 are considered moderately segregated, and cities with a measurement over 60 are considered very segregated (Massed and Denton 1993, p. 20). One of the main reasons that the DI is the most widely used because it can be consistently constructed with the census data that is available during the time you are looking at, and this is and easy way to compare censuses numbers from different times in a consistent manner (Boustan, p. 1).
As far as it goes for exposure or isolation, meaning, how isolated a certain group or race is, the way that it is typically measured is through isolation measures. Determining “the percentage of residents black in the census tract of the typical black in metropolitan” areas usually does this, and this can also be done with the white areas, and if the “whites tend to live in almost all white census tracts,...