Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Stephen C. Farber


The distribution patterns of toxic sources in Louisiana reveal that some communities may be disproportionately exposed to potential environmental risks. This dissertation examines whether the location and environmental control behavior of toxic polluters are systematically related to the socioeconomic and racial characteristics of communities. The study identifies who lives in the immediate proximity of toxic sources and determines whether the characteristics of these communities are different from those of Louisiana's general population. The results reveal that income levels in communities that host toxic sources are consistently and significantly lower than the state averages. A distance gradient analysis indicates that as distance from the nearest toxic source increases, the mean percentage of blacks in the community decreases and the mean percentage of whites increases. The results provide support to the hypothesis that low income and minority groups are disproportionately exposed to environmental risks. The study also tests whether changes in potential exposure to risks differ significantly across socioeconomic groups. The estimation results indicate that the higher the income levels, the more educated, and the more politically active the community, the greater the reductions in toxic discharges over time. Furthermore, the greater the percentage of blacks in a community, the greater the reductions in discharges. In terms of relative importance, income is a more important factor than race in explaining aggregate reductions in discharges.