SPATIAL DEPENDENCY OF SEGREGATION INDEXES

A few researchers have mentioned the scale sensitivity of segregation index, D. In this paper, I discuss analytically and empirically why us ing large enumeration areal units usually results in low segregation m easures, and using small areal units produces relatively high segregat ion measures. The discussion is also applicable to the multigroup vari ant of D. A major finding is that if people of the same ethnic groups are positively spatially autocorrelated, increasing the size of areal units of analysis may not lower D initially, because only people of th e same group are added. But enlarging the areal units subsequently may include population of other ethnic groups, and therefore could lower D. However, if the boundaries of the larger enumeration units are draw n to include only population of the same group, then D will not change significantly. Both the spatial autocorrelation of ethnic group popul ation and zonal pattern are critical factors in determining the scale sensitivity of D.