*By Carlo Versano* The multi-year Women in the Workplace report, produced by Sheryl Sandberg's Lean In organization with McKinsey & Company, reveals a stubborn problem of gender diversity in corporate America. As Rachel Thomas, the president of Lean, explained to ChedHER on Friday, that companies are clearly interested in closing the gender gap ー but they haven't done enough to make it happen yet. "Women are doing their part," Thomas said. "What do companies need to do?" Sandberg, the COO of Facebook ($FB), and Thomas penned an [op-ed](https://www.wsj.com/articles/sheryl-sandberg-on-what-companies-need-to-do-to-lean-in-1540267620) for The Wall Street Journal after the release of the report outlining that "disconnect." Thomas cited data showing women are asking for promotions and raises at the same rate as men and ー contrary to popular thinking ー do not leave the workplace at a higher rate. Yet they still remain "underrepresented at every level" of the corporate ladder. One of those reasons, according to Thomas, is a form of performance bias that is widespread and stubborn in the hiring process: men's performance is slightly over-estimated, while that of women is slightly under-estimated. "As a result, men are often hired and promoted based on their potential," Thomas said. "And women are often hired and promoted based on what they've accomplished." That is particularly problematic for entry-level hiring, where men and women have less differences in accomplishments between them. It's part of a "pipeline" problem that Lean In is trying to correct. Companies need to start thinking of gender diversity as a "must have" and not just a "nice to have," Thomas said. For full interview [click here](https://cheddar.com/videos/the-president-of-lean-in-tells-us-how-companies-can-improve-their-workplace-culture).
