“There’s a big perception gap,” said Stacey Haas, the partner at McKinsey who steered the study.

This is, to be sure, not only an American problem. When British companies were forced to reveal their salary data recently, and it became glaringly clear that women were paid less than men, Burberry and other companies blamed the gap on the fact that most of their C suite executives were men. And given that C suite salaries are the highest — well, the math makes sense. The French brand Dior appointed its first female designer only in 2016; Givenchy in 2017.

But it is interesting, given that such a large portion of the original wave of American designers and founders were women: Claire McCardell, Bonnie Cashin, Anne Klein, Liz Claiborne. Especially because there are currently no barriers to entry for women and, Ms. Haas said, “there is no aspiration gap.” At the beginning of their careers, the study found that women were 17 percent more likely than men to want to get to the top. The problems come later.

The idea for the survey originated with the CFDA around the time of the women’s march in 2017, when a number of its members headed down to Washington. Cindi Leive, then the editor of Glamour, signed on, and McKinsey created a 100 question survey for both men and women at all stages of their careers and developed the protocol for the study.

A list of companies was compiled that included mass and designer fashion, retail and production, and 191 agreed to participate. The companies disseminated the survey, which was anonymous, to employees as they chose, and 535 people responded; 20 in-depth interviews were also held.

But the end product doesn’t distinguish between responses on the creative, corporate or retail side, or the mass market versus the designer sector, which logic dictates have some different structural challenges. And “a few very big companies that are important in the industry declined to participate,” said Steven Kolb, the chief executive of the CFDA, who declined to name them.

“I don’t know if they got tangled up in H.R., or there was a legal reason, or if they were just concerned about what they would find out,” Mr. Kolb said.