Image caption More than half of US medical school graduates are female, a new study found
A study has found that women who study medicine tend to earn around $2 million less over a lifetime than their male colleagues.
They also earn 9% less than white women, and 10% less than African-American women.
Researchers measured the earnings of almost 400,000 doctors over a 20-year period.
It was the first nationwide study to break down the impact of bias and sexism in professions.
“We basically had a lot of data across the country,” says Rachel Lampson, co-author of the analysis and fellow at the Hamilton Project, an influential think-tank at the Brookings Institution.
“That way we were able to be confident in the methodology of the research.”
The study by Ms Lampson and economist Marcel Fratzscher was based on data from 1996 to 2016, drawn from the official Department of Health and Human Services medical school placement records, which are held in the National Practitioner Data Bank.
Using that database they established a cohort of doctors. Of those, 9% were black, 10% were Asian, 57% were white and 7% were Hispanic.
Image copyright Getty Images Image caption Being a woman was linked to earning less than a white male colleague
Women also were more likely to make less than white men on average than the black and Hispanic male colleagues.
Ms Lampson says this disparity is not really surprising and could be partly because of the fact that black women are more likely to work full-time whereas white male doctors tend to work longer hours.
Overall, they found that the difference in earnings among women and men was 8% lower.
Photo caption Women face discrimination in business as well as in academia
Black and Hispanic men earned 15% and 9% less than white male colleagues respectively, according to the study, which was published on Wednesday in the Journal of the American Medical Association.
“The report is extremely convincing,” said Barbara Perry, a professor of health and social policy at the University of Washington.
“It makes it clear that black and Hispanic women have lower earning prospects than their white female counterparts.”
“It’s not a minor difference. This is a big issue. It’s important that all of us should be able to do what the average white guy can do.”
It has long been recognised that men do better in college than women, and that more men than women also set themselves up for higher starting salaries.
But there has been less research on the impact of this on people’s wages in later years.
Since 1996, some 90% of the roughly 290,000 doctors who have been included in the National Data Bank had completed a residencies, where they tend to work for several years.
This study revealed that doctors who were female on average earned $60,000 less than doctors who were white male, $122,000 less than black doctors and $119,000 less than Hispanic women.
The gender pay gap is not exclusive to doctors. It was also found that women who followed family medicine and obstetrics got paid less than other medics in those fields.
“You see a correlation with the family physician who focuses on family care,” said Ms Lampson.
“We’ve made assumptions that family medicine is boring. And it is, but it is also very important.”
Black doctors did the best, earning $5,020 more than a white doctor.
Women in other specialities such as obstetrics, surgery and pediatrics got paid $1,172 more than white colleagues.
“There have been enormous changes over the last 20 years,” said Tom Fudge, a professor at the University of Pennsylvania School of Medicine who has done similar research.
“Women have played a more integral role in the training of doctors.”
He says the future may brighten for women if they can keep their hearts healthy.
“In the future, doctors may earn more because they’re healthier,” he said.
“More women are getting heart disease diagnoses.”