Spatial and aspatial residential segregation measures: Salt Lake County 1999 to 2007

Traditional aspatial segregation indexes have two weaknesses: the Modifiable Areal Unit Problem (MAUP) and the checkerboard problem. These challenges occur because of the reliance on abstract definitions of geographical boundaries. Presently, no aspatial measure exists that eliminates all challenges of aspatial measures. This thesis applies the use of a new spatial approach. This approach does not rely on predefined geographical boundaries and essentially elements all inherent weaknesses of aspatial measures. The materialization of spatial measures is possible through the advent of Geographic Information Systems. The use of a spatial segregation program, created in 2007, and run through ArcGIS 9.2, is applied to Salt Lake County from 1999 to 2007. The program calculates a weighted group composition of the local environment for each individual. Two indexes are calculated through the spatialseg program: the Dissimilarity Index (D) and the Spatial Information Theory or Entropy Index (H). The spatial information theory segregation index measures the variation in the diversity of the local environment of each individual. The dissimilarity index measures the proportion of people who would need to change their residence in order to achieve an even distribution. Aspatial as well as spatial results are calculated for each index and for each year: 1999, 2001, 2004, and 2007. Various radii are also associated with each calculation. These radii of 500m, 1000m, 2000m, and 4000m indicate the degree and extent of the distribution of segregation. Three groups are compared through analyzing the scale and size of segregation. These groups are associated with data obtained from the Utah Population Database regarding undocumented illegal immigrants, legal immigrants, and native residents of the U.S. Overall, the analysis finds that the spatial approach presents different and advantageous benefits that the aspatial approach cannot compute or calculate. These advantageous benefits are associated with the extent and scale of segregation indicated by the macro/micro ratio obtained by comparing macroscale regions of 4000m to microscale regions of 500m. The results of the macro/micro ratio suggest a temporal change in the spatial distribution of immigrants, undocumented illegal immigrants, and native residents. The results of the macro/micro ratio indicate that the undocumented population in Salt Lake County has a different and unique spatial distribution that is not evident for native residents as well as legal immigrants.