Seventy five percent of the pay gap in Denmark comes from productivity differences between men and women

See Denmark fact of the politically incorrect paper of the day by Tyler Cowen.

"Using Danish matched employer-employee data, this paper estimates the relative productivity of men and women and finds that the gender “productivity gap” is 12 percent–seventy five percent of the 16 percent residual pay gap can be accounted for by productivity differences between men and women.

That is from the job market paper of Yana Gallen, a job market candidate from Northwestern."