FIGURE 4.2 Map of Allegheny County, Pennsylvania municipalities. Relocation areas that meet the hypothetical user criteria are marked in gray. SOURCE: Johnson, 2002.

It is said that rising tides lift all boats, but there are clear winners and losers in the economic boom of the late 1990s. Research is needed to address the underlying causal mechanisms and consequences of the economic and social factors that result in poverty, segregation, homelessness and other urban ills. Box 4.2 provides an example of how GIS can be used to analyze poverty concentration. Data from the 2000 Census may stimulate new research to document trends in poverty concentration and racial segregation.

Much research has been done on patterns of poverty concentration and racial segregation, but many questions remain unanswered or inconclusive, for example, the role of socio-economic class versus race in determining segregation patterns. New multiple-scale segregation measures using GIS (Wu and Sui, 2001), as well as theoretical perspectives such as Sen’s entitlement theory (Sen, 1976), can be applied to these efforts to explain the housing situation of the urban poor. In addition, the growing urban digital divide—the existence of the information-rich and the information-poor— should be taken into account.