This paper investigates the influence of racial and ethnic composition of labor markets on earnings inequality among Black, Hispanic, Asian, and white men to determine whether the influence of minority regional concentration on earnings differs by educational level. Consistent with other studies, this analysis, based on the 1980 Public Use Microdata Samples, produced negative additive effects of such concentration on the earnings in 1979 of nonwhite and Hispanic men. Results showed that minority workers lose financially from the labor market concentration of other nonwhites, whereas whites benefit, no matter what the educational level. This finding suggests that both competition and discrimination operate to economically differentiate workers along racial and ethnic lines. Furthermore, educational level widened rather than narrowed white-nonwhite earnings differences. As expected, whites benefit most from the presence of a large minority work force, while blacks lose the most. However, results with respect to Hispanics and Asians are somewhat ambiguous. This suggests that their distinction from whites is based largely on ethnicity rather than race and further implies that Asians and Hispanics, but not blacks, may eventually reach socioeconomic parity with whites as they advance in their cultural assimilation. (Author/ETS)