When it comes to Silicon Valley, Asians are an overrepresented population in the workforce. Even among the tech industry's most valuable companies, two of the more visible CEOs, Google's Sundar Pichai, and Microsoft's Satya Nadella, are both Indian. Which is why it might come as a surprise that Asians—especially Asian women—are among the least likely to be promoted into leadership positions, according to a new study from Ascend Leadership, a nonprofit group for Asian professionals.

“That’s why we call the report the Illusion of Asian Success,” says Buck Gee, a former vice president at Cisco and one of the authors of the study. The natural assumption is that if Asians are more prevalent in the workforce, they will be more prevalent at the top. But “when you look at the hard data, that is a fallacy,” says Gee.

Gee and his co-author Denise Peck, also a former vice president at Cisco, studied a data set of 184,776 employees, 63,299 managers, and 12,856 executives, information collected by the Equal Employment Opportunity Commission between 2007 and 2015 from technology companies in the San Francisco and San Jose areas, a group that covers Apple, Facebook, Cisco, Twitter, Intel, HP, and Yelp. (The EEOC has this data because Title VII of the Civil Rights act requires private employers with more than 100 employees to submit confidential reports.) The study focuses only on the promotion within an organization, not hiring or retention. The authors measured leadership representation by comparing the percentage of entry-level “professionals” from a particular group, say Asian women, the percentage of “executives,” according to job categories in the EEOC reports, which also includes “administrative support” and “service workers.”

After sifting through the data, the authors concluded that race is a stronger impediment than gender when it comes to climbing Silicon Valley’s corporate ladder. Representation of white women in leadership roles improved by 17 percent between 2007 and 2015, whereas for all other minority groups, the percentage went down.

“White women are continuing to benefit from the system of racism, even when they are also experiencing discrimination because of their gender,” says Hannah Lucal, associate director at Open Mic, a nonprofit group that works with socially conscious investors. Lucal says that companies should approach the issue with an understanding that sexism and racism are structural issues that always operating in tandem, rather than interpret studies like this as a hierarchy of discrimination.