Growth in the number of PhDs awarded in some academic disciplines has far outstripped that in others, evidence submitted to the research excellence framework shows.
The percentage increase in doctoral degrees awarded in the social sciences during the REF period was 35 per cent, compared with just 18 per cent in medical and life sciences, for example.
The push to improve completion rates in disciplines that traditionally take longer to submit PhDs could be one factor behind the trend, according to a dean of arts and social sciences.
Universities had to give information about the number of PhDs they had awarded in each discipline as part of their submission to the environment section of the REF, which accounted for 15 per cent of their total score.
Details about the number of PhDs awarded by main panel, which are listed in a series of panel overview reports published by the Higher Education Funding Council for England, track the percentage increase in doctoral awards from 2008-09 to 2012-13.
The biggest percentage jump in awards over the assessment period was in the social sciences, up 35 per cent, followed by the arts and humanities (31 per cent). The smallest percentage increase, 18 per cent, was in medical and life sciences, while the physical sciences recorded a rise of 24 per cent.
Even though social sciences and arts and humanities outpaced other fields, the absolute number of awards in 2012-13 was still higher in the medical, life and physical sciences.
Katie Normington, dean of arts and social sciences at Royal Holloway, University of London, suggested that there could be a number of factors behind the rises in the social sciences and the arts and humanities.
Many PhD students in these subjects are self-funded, whereas grants are the norm in the sciences, she said. “There is the potential there for [the number of self-funded students] to grow and develop because they are not waiting for external bodies or external scholarships.”
Another factor could be the drive to improve PhD completion rates. In the past few years, most institutions have introduced regulations requiring students to submit their thesis within a maximum of four years of study.
This may have spurred many more social scientists and artists to submit in a shorter time than they might have previously, she said.
“A lot of the science students are already working in labs with supervisors on projects that have a particular timescale to them, so it may well be that it has affected them less,” she added.
There was also a possibility that institutions provided extra funding for PhD students to raise their numbers for the REF, Professor Normington said. However, she continued, the rise in awards was more likely to be an independent trend that went beyond “game-playing”.
The Arts and Humanities Research Council said that the growth indicated the “ongoing attractiveness” of the in-depth study and research provided by arts and humanities PhDs and the “repositioning” of the qualification to offer “wider employment opportunities”.
AHRC research found that PhDs in art and design subjects enjoyed particularly strong growth of about 90 per cent during the REF period.