The report, titled "Do Graduate Degrees Pay Off" by the Postsecondary Education and Economic Research Center and released in March, shows psychology graduate degrees produce the weakest outcomes, with a negative return on investment of 8%.

To calculate the estimates, research authors Altonji and Zhengren Zhu, a professor at Vassar College, analyzed data from roughly 800,000 students over three decades at Texas public universities, producing causal estimates for 121 advanced degrees.

The analysis estimates how much a graduate degree increases lifetime earnings after accounting for total costs, including tuition fees, and the income students could have earned had they not pursued further study.

Once adjusted for these factors, the gains in lifetime income are often smaller than the raw increase in earnings, the report said.

Clinical psychology, a specialized branch of the field, also records negative returns of around 5%, while social work and curriculum and instruction degrees similarly show negative outcomes.

"If you’re thinking about graduate school, you want to get some information about what the earnings potential is coming out of the degree as well as the kinds of occupations and jobs it leads to," Joseph Altonji, a professor of economics at Yale and co-author of the study, told Fortune.

Graduates from Boston University, U.S. Photo courtesy of the university

Overall, graduate degrees still increase earnings by about 17% on average.

Despite concerns that AI could disrupt law and business jobs, degrees in these fields continue to deliver positive returns, with law graduates seeing cost-adjusted returns of 41% and MBA holders about 13%.

Medical and pharmacy degrees offer the strongest outcomes, with earnings nearly tripling for medical doctorate holders and rising by more than two-thirds for those with pharmacy doctorates, according to the New York Post.