A Measure of Gender Wage Discrimination at Quantiles

Revised: 2006-05.-- Published as an article in: Journal of Population Economics, 2007, vol. 18, issue 1, pp. 165-179.

The literature provides several scalar measures of gender wage discrimination that cannot identify whether discrimination is greater among high earners or among low earners. Furthermore, two populations may exhibit the same value of the scalar measure while discrimination could be very differently distrubuted. We extend Oaxaca's scalar measure to any quantile of the distribution of wages. Our measure allows comparisons within a population and inter-population. Using the Spanish Survey of Wage Structure we find that gender wage discrimination increases with the quantile index but as a fraction of the gender wage gap reaches a maximum at the ninth percentile.