Monday, January 14, 2002

Methodology
Segregation scores based on census data


By The Detroit News

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   What do we mean when we say "segregation," and how do we measure it?
   This report explores the segregation of Metro Detroit neighborhoods -- their strong tendency to be almost all-white or all-black. Like academic researchers who study the issue, The Detroit News measured this separation using a statistical tool called the index of dissimilarity.
   The formula compares the neighborhood percentages of two groups -- in this case, blacks and whites -- to those of the entire metro area.
   In its analysis, The News used census tracts as neighborhoods; these are Census Bureau-defined areas of roughly 4,000 people each with borders that follow major roads, waterways and other features.
   Zero represents perfect integration: The makeup of each neighborhood exactly matches that of the entire metro area. A 100 would mean total segregation: Each neighborhood is 100 percent black or 100 percent white.
   The News calculated a score of 85 for the Detroit metro area. Think of it this way: 85 percent of Metro Detroit's blacks would have to move to a different neighborhood to achieve "perfect" integration.