Using a complex analysis, Dr. Stevenson showed that increasing girls’ sports participation had a direct effect on women’s education and employment. She found that the changes set in motion by Title IX explained about 20 percent of the increase in women’s education and about 40 percent of the rise in employment for 25-to-34-year-old women.

“It’s not just that the people who are going to do well in life play sports, but that sports help people do better in life,” she said, adding, “While I only show this for girls, it’s reasonable to believe it’s true for boys as well.”