A book titled for the declining significance of this variable by Blau, (-5[2])Brinton, (-5[1])and Grusky looks at whether there is an “Opt-Out Revolution” proposed by Belkin. Ronald Oaxaca (“wah-HAH-kuh”) co-developed the Oaxaca-Blinder decomposition to study this variable. Comparable worth policies usually try to reduce the impact of this variable. This variable’s change from correlating with decreased to increased education in the United States is linked to the rise of (*) office work. The impact of this variable on labor force participation rates over time is depicted in a U-shaped curve created by Claudia Goldin. The impact of this variable on pay was the subject of the case Ledbetter v. Goodyear Tire. For 10 points, name this variable that impacts whether people are affected by the “glass ceiling.” (10[2])■END■ (10[2])