This trend is affected by whether they had a master’s degree, funding for their program, marital status and the educational attainment of their parents. The study looked at data from 1990 to 2009 and excluded international students, tracking data for U.S. citizens and legal permanent residents.
According to the study, when it came to doctoral students without a master’s degree, African Americans took longer to finish than Hispanics, who took longer to finish than other groups.
The study also points out that students who were funded — either with research assistantships or teaching assistantships — finished their degrees faster than those who had to pay themselves or take out loans to pay for their education. The role that funding plays is substantial to the time it takes to finish, according to the study.
Source: American Institutes for Research, How Long Does It Take? STEM Ph.D. Completion for Underrepresented Minorities, January 2, 2013.