Data on the Spectral Segregation Index,
by Federico Echenique and Roland Fryer

In the paper "A Measure of Segregation Based on Social Interactions" (Quarterly Journal of Economics, 122(2), May 2007), we propose a measure of segregation called the Spectral Segregation Index (SSI), and use it to measure residential segregation at the level of census blocks for 300 Metropolitan Statistical Areas.

You can download the data on block-level SSI here: The files blocklevel_SSI_1990Census.txt.gz and blocklevel_SSI_2000Census.txt.gz contain the data for the 1990 and 2000 Census, respectively. These are gzipped tab-delimited text files. A description of the variables in the files is: here.

Here is the data in stata format: blocklevel_SSI_1990Census.dta.gz and blocklevel_SSI_2000Census.dta.gz

We also generated a segregation map of Los Angeles, where each block is color-coded according the the level of segregation of the predominant ethnic/racial group. The presents the city divided into three-digit zip codes for ease of reading. We generated a map for all Non-whites and separate maps for each race/ethnicity:

We thank Delia Crigg for her excellent assistance in generating these maps.
Matlab files for calculating the indices are: These files are also in Roland's page.