Social Scientist, Harvard University

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Segregation Calendar

Each box to the right represents a neighborhood in a city. In technical terms, a neighborhood is usually a Census Tract and a city usually has far more than 12 Census Tracts. Measures of Segregation are sensitive to the choice of areal unit used in calculating segregation. 

Fill in the population, % white, and % black of each Tract in order to calculate the Dissimilarity and Isolation Indices for the city. You can also generate a random population.

Most indices of segregation are calculated for only two groups (so, in this case, % black and % white must add up to 100%).

Tract 1:

Tract pop:

% white:

% black:

Tract 2:

Tract pop:

% white:

% black:

Tract 3:

Tract pop:

% white:

% black:

Tract 4:

Tract pop:

% white:

% black:

Tract 5:

Tract pop:

% white:

% black:

Tract 6:

Tract pop:

% white:

% black:

Tract 7:

Tract pop:

% white:

% black:

Tract 8:

Tract pop:

% white:

% black:

Tract 9:

Tract pop:

% white:

% black:

Tract 10:

Tract pop:

% white:

% black:

Tract 11:

Tract pop:

% white:

% black:

Tract 12:

Tract pop:

% white:

% black:


This web form allows you to calculate two common measures of segregation. There are many measures of segregation and a useful summary of the most common can be found on the U.S. Census Bureau housing website . The two measures calculated here are Dissimilarity and Isolation. These two measures represent two of the five dimensions of segregation identified by Massey and Denton (1988). The five dimensions are evenness, exposure, concentration, centralization, and clustering. Dissimilarity is a measure of evenness, which is generally the differential distribution of two groups across areal units of a city. Isolation is a measure of exposure, which is generally the potential for contact by members of a different groups within a city.

 

Dissimilarity

Dissimilarity measures the percentage of a group's population that would have to change residence for each neighborhood to have the same percentage of that group as the metropolitan area overall. The index ranges from 0.0 (complete integration) to 1.0 (complete segregation). 

The formula for Dissimilarity, D, is: 

where T is the total population of the city, P is the proportion minority of the city, ti is the total population of areal unit i, pi is the proportion minority i, and there are n areal uni…

where T is the total population of the city, P is the proportion minority of the city, ti is the total population of areal unit i, pi is the proportion minority i, and there are n areal units in the city.

Isolation

Isolation measures the extent to which members of a minority group are only exposed to members of their own group. A measure of 1 means perfect isolation, .5 means equal chance of exposure to either group, and 0 means that a member of a minority group has no chance of contact with members of their own group. 

The formula for Isolation, P for group x, is: 

where the notation is the same as for Dissimilarity and, additionally, X is the minority population of the city and xi is the minority population of i. 

where the notation is the same as for Dissimilarity and, additionally, X is the minority population of the city and xi is the minority population of i. 

 

Source: Massey, Douglas S. and Nancy A. Denton. 1988. "The Dimensions of Residential Segregation". Social Forces 67, (2), pp. 281-315.