  Decomposition analysis is a critical tool for understanding the social and
spatial dimensions of segregation and diversity. In this paper, I highlight the
conceptual, mathematical, and empirical distinctions between segregation and
diversity and introduce the Divergence Index as a decomposable measure of
segregation. Scholars have turned to the Information Theory Index as the best
alternative to the Dissimilarity Index in decomposition studies, however it
measures diversity rather than segregation. I demonstrate the importance of
preserving this conceptual distinction with a decomposition analysis of
segregation and diversity in U.S. metropolitan areas from 1990 to 2010, which
shows that the Information Theory Index has tended to decrease, particularly
within cities, while the Divergence Index has tended to increase, particularly
within suburbs. Rather than being a substitute for measures of diversity, the
Divergence Index complements existing measures by enabling the analysis and
decomposition of segregation alongside diversity.
