Abstract
Our study investigates the diversification and fragmentation theses, fueled by claims that greater diversity is reshaping the social fabric of American life and that the United States is an increasingly fragmented nation. We take a multidimensional view of heterogeneity that considers whether growing ethnoracial diversity within U.S. communities (i.e., incorporated and unincorporated places) has resulted in the consolidation or differentiation of demographic, sociocultural, and economic distinctions between 1980 and 2010. As communities have become more ethnoracially diverse, they have become more heterogeneous in language and nativity-two characteristics tied closely to Latino and Asian population growth. However, ethnoracial diversity within communities is only weakly associated with household, age, educational, occupational, or income heterogeneity despite large racial/ethnic differences in these characteristics nationally. This trend does not apply to all forms of ethnoracial diversity equally: Hispanic and especially Asian population growth is more likely to generate community sociodemographic and economic heterogeneity than is black population growth. Consistent with the fragmentation hypothesis, we also find that broader geographic context matters, with more ethnoracially diverse metropolitan and micropolitan areas experiencing reduced social and economic heterogeneity inside their constituent places. We conclude by discussing the social implications of these patterns for intergroup relations, spatial exclusion, and ethnoracial inequality.