Using data from the 1971 National Longitudinal Survey of middle-aged males, this survey simultaneously examines wage differentials in unionized and nonunionized employment in both the public and private sectors. Unlike previous studies conducted by Daniel S. Hamermesh, and Walter Fogel and David Lewin, this study includes a large sample that is employed (1,744 whites and 713 blacks), and utilizes controls such as the effect of individual characteristics, region, city size, and occupation group. Within a human capital framework, separate differentials are estimated for white-collar and blue-collar workers, and for whites and blacks. The data indicate that public sector unions have been unsuccessful in raising the earnings of white-collar employees in government, but that they have raised the earnings of blue-collar workers. The evidence also suggests that collective bargaining is more profitable for blacks than whites in the private sector, but that in governmental positions its effect is the same for both racial groups. In general, government unions are not more powerful than their private counterparts since the earnings of unionized public workers are either equal to or somewhat below those of private unionized employees. (Author/ELG)