Despite the fact that twice as many women as men sign off on audits performed by the seven largest accounting and auditing firms, fewer of them are partners, a study published in the Journal of Accounting and Public Policy has found.

The study, published earlier this year but reported by CPA Practice Advisor on Monday, describes this “vertical gender segregation” as resulting in the director level being a “pink collar ghetto,” a term originally coined in 1983 to describe so-called “women’s work,” and its corresponding low wages and limited advancement opportunities. This term was reimagined in 2011 by various gender parity researchers studying women in industries such as private equity, real estate, venture capital and tech.

“Women and men are hired into these public accounting firms at a very equal ratio, but at the partner level, it’s disproportionate,” said co-author M. Kathleen Harris, an assistant professor of accounting at Washington State University’s Carson College of Business and one of the study's authors. “If we want equity in accounting, then both men and women need to be at the table making decisions.”

The authors analyzed more than 1,500 audit engagements from the 2017 Federal Audit Clearinghouse for the seven largest public accounting firms. The study is limited to U.S. nonprofits, which are required to make these data accessible because they are public institutions.