An intuitively appealing method for estimating gender wage gaps by industry is shown to yield estimates that vary according to the arbitrary choice of left-out reference groups for non-industry categorical variables, such as race and marital status. This study uses data from the Current...

Applying a new decomposition method to U.S. PSID and Danish Longitudinal Sample data, the authors compare how U.S. and Danish gender wage gaps developed between 1983 and 1995. In Denmark, they find, the wage gap widened, because the worsening in women's relative returns to observable human...