While male and female surgeons both work equally hard saving lives in the operating room, women in general surgery project earning significantly less than men. This disparity is due to women underestimating their future earning power and to differing approaches to salary negotiation, according to an important new study from LA BioMed, an independent non-profit biomedical research organization.

In recent months, LA BioMed sent out anonymous questionnaires to 607 general surgical residents at 19 residency programs across the U.S. More than 70 percent of them completed the survey — 44 percent were female.

When asked what an ideal salary would be after finishing residency, female surgeons on average expected to be paid $30,000 a year less than men.  This suggests that women surgeons undervalue their worth relative to similarly trained men.

One underlying reason behind those different expectations: women surveyed did not feel nearly as comfortable as men asking for more money. Female respondents were significantly less likely than males to feel they had the right tools to negotiate their salary. They also found the whole process of negotiating less appealing than their male counterparts and were less likely to look for other job offers as a negotiating tactic.

The women surveyed were not choosing lower-profile jobs: both the male and female respondents reported no difference in the number of hours they expected to work, or their desire to hold leadership positions or pursue academic or research over 30-year careers. In the U.S., residency salaries are standardized by hospital and state guidelines, providing gender equity, but after completing training it is up to the individual doctor to negotiate their compensation package.

“Female residents in our study undervalued their annual future earning potential by an average of $30,000 as compared to their male counterparts. Over the span of a 30-year career that is nearly one million dollars,” says Dr. Christian de Virgilio, LA BioMed researcher and the Chair of the Department of Surgery at the UCLA-Harbor Medical Center.

On top of their lower pay expectations, the women who answered the survey also felt that they’d have more responsibilities at home than the men with regard to their significant others. That has plenty of down-the-line consequences, including the fact that the female surgical residents surveyed were less likely to be married or have children than the males.

“Our study helps us better understand gender salary disparities in surgery” says Kelsey Gray, General Surgery Chief Resident at UCLA-Harbor Medical Center.