One study by four economists even found that expanding opportunities for women and African Americans over the last 50 years has offered a serious boost to U.S. productivity growth:

Fairness, they contend, has made the economy more productive. Chang-Tai Hsieh, Erik Hurst, Charles Jones and Peter Klenow argue that as much as 20 percent of the growth in productivity in the United States over the past 50 years can be attributed to expanded opportunities for women and blacks.

“Changes in things that have affected women or blacks specifically have yielded a sizable impact on overall U.S. earnings growth,” Hurst told me. “That is a big effect.”