There are notable racial and economic differences associated with the types of graduate degrees students pursue and whether they complete their programs. Based on 2008 data, 39 percent of students who as undergraduates came from households in the lowest income quartile pursued graduate degrees; 45 percent who came from the highest quartile of household income went on to do the same.

And while 76 percent of the wealthiest quartile of students completed their graduate programs after 10 years, only 64 percent of those who grew up in the lowest quartile did so. Because of data limitations, those figures capture students who entered graduate programs in 1993.

More recent data show that though a larger share of black bachelor’s degree holders go on to graduate programs than any other racial group, a quarter of that group enrolls at for-profit institutions that are viewed as being less academically rigorous. Around 6 percent of Asian Americans, Hispanics and whites enrolled in for-profits. Asian Americans and white students are also more likely to pursue doctoral and professional degrees than their black and Hispanic peers. The same disparities exist along economic lines. Also true: Whites, Asian Americans, and wealthier students are more likely to have completed a bachelor’s in the first place, so they account for a larger population of graduate-school students.

Data from other sources show that black and Latino students each make up about 6 percent of the population enrolled in doctoral programs. Some university leaders blame the culture of recruitment for the lackluster numbers. “Everything has to be at scale or there’s no effect,” Arizona State University President Michael Crow said last year. He added that universities “have to want to do that.”

Urban Institute

“There are all sorts of reasons why people from more affluent families would be more likely to go to graduate school,” Baum said. One may be that there’s more money around for higher-income students to enroll at the higher-paying graduate programs. “Another reason is that they may have higher expectations about it,” she said. “If their parents went to graduate school, then going to graduate school seems like the normal thing to do.”

To be sure, graduate degrees—even the programs that don’t lead to six-figure incomes—typically are a financial win for the students who complete them. And unlike the debate of whether undergraduate educations increase a student’s skill set or merely signal to employers a competency that may or may not be warranted, “Graduate education is much more vocational (than undergraduate educations),” Baum said. “You are learning very specifically how to be prepared for an occupation.”

She added: “There are people who get master’s degrees in generalized fields and they get jobs in something else. And certainly that credential has a signaling impact, but I would say that the vast majority of graduate degrees really are things that people use in their professions, and they’re required—not just as a signal.”