Bargaining unit composition and the returns to education and tenure

Using data on collectively bargained outcomes in Pennsylvania schools in 1983-89, the authors find a strong relationship between the returns to education and tenure and the distribution of those attributes in the bargaining unit. For instance, the higher the median level of teacher tenure in a district, the greater was the pay gap between teachers with low and high tenure. This relationship was very strong in districts with vigorous community support for union activities and weak or nonexistent in districts with low union support. The authors argue that, consistent with the "median voter model," the unions in this study pushed hardest to advance the interests of their typical members, and that they were most effective in doing so where the community was generally supportive of unions.