Measures of Spatial Segregation

Sean F. Reardon, Pennsylvania State University
David O'Sullivan, Pennsylvania State University

The measurement of residential segregation patterns and trends has been limited by a reliance on segregation measurements that do not appropriately take into account the spatial patterning of population distributions. We define a general approach to measuring spatial segregation among multiple population groups. This general approach allows researchers to specify any theoretically-based definition of spatial or social proximity desired in computing segregation measures. Based on this general approach, we develop a general spatial exposure/isolation index and a set of general multigroup spatial evenness/clustering indices. We review these and previously proposed spatial segregation indices against a set of eight desirable properties of spatial segregation indices. We conclude that the spatial exposure/isolation index--a measure of the average composition of individuals' local spatial environments--and the spatial information theory index--a measure of the variation in the diversity of the local spatial environments of each individual--are the most conceptually and mathematically satisfactory spatial indices.