How does collective bargaining affect the gender pay gap?

The authors study the effect of unionization on gender wage differentials for production workers in nine U.S. manufacturing industries. They find that the wage gap is significantly smaller in unionized establishments for six of the industries, even after controlling for occupation and establishment gender composition. But this union effect does not hold within three industries. The authors conclude that unionization generally reduces wage inequality between blue-collar men and women, but the effect might be contingent both on the overall proportion of women in an industry and on union characteristics. The authors discuss the implications of these findings for income inequality and union policies.