Trajectories of Ethnoracial Diversity in American Communities, 1980-2010

The ethnoracial makeup of the US population has undergone transformative change during recent decades, with the non-Hispanic white share of the population shrinking while the minority shares expanded. Yet this trend toward greater diversity is not universal throughout the country. We propose a framework of segmented change, which incorporates both spatial assimilation and ethnic stratification theories, to better understand variation in patterns of diversification across American communities. Our research applies growth mixture models to decennial census data on local communities (census "places") for the period 1980-2010, finding that trajectories of ethnoracial diversity are much more uneven than popularly thought. Moreover, types of diversity change are stratified by initial racial composition. While places with mostly-white populations in 1980 underwent extensive diversification, places with larger shares of Hispanics and (especially) blacks in 1980 exhibited less uniform movement toward diversity and were more likely to remain racially homogeneous. Analysis of the underlying group-specific pathways of change indicates that the diversification of white communities was driven largely by Hispanic growth; when areas with a black presence did diversify, it occurred via contracting white populations. These racially conditioned and locally variable patterns emphasize the segmented nature of diversity change in American society.