Universities are increasingly demanding that new academics hold doctorates in a trend that some believe could accelerate when the tuition-fee cap rises to £9,000 a year.
The proportion of UK academic staff with doctorates rose from 48 per cent in 2004-05 to 50.1 per cent in 2009-10, according to data prepared for Times Higher Education by the Higher Education Statistics Agency.
Some pre-1992 universities, such as City University London and Birkbeck, University of London, have made PhDs a standard job specification for all new scholars.
City only recently made PhDs compulsory. Paul Curran, its vice-chancellor, said: "All of our new permanent academic staff are expected to engage in high-quality research and so, as a minimum, we require them to have a doctorate.
"Of course, such a research expectation would not be reasonable for new academic staff who join us without research training, and so we support them to obtain a doctorate before their contract is made permanent."
The proportion of academics with doctorates is already far higher in pre-92 universities (62.7 per cent in 2009-10) than in post-92 ones (29 per cent).
But the figures may become more significant under the new fee regime: in the US, it is common for colleges to advertise the proportion of staff with doctorates in a bid to woo prospective students.
For example, Swarthmore College, a private liberal-arts institution in Pennsylvania, says on its website that 98 per cent of its "expert, stimulating and diverse" faculty "hold PhDs or other terminal degrees".
Roger Brown, professor of higher education policy at Liverpool Hope University, said he thought it likely that doctoral rates in the UK, where the undergraduate tuition-fee cap is set to treble in 2012, would continue to increase.
"I am sure that market competition, whether or not we get price competition, will ultimately accelerate that trend," he said.
Professor Brown cautioned that there was "no support" for the notion that PhDs equate to competence in teaching.
However, he acknowledged that teaching by postgraduate students was already a source of resentment among some undergraduates.
"I think the question of who you are going to be taught by is something students, particularly in research-intensive universities, are going to raise," he said.
Horses for courses?
Not only do pre-92 universities have a higher proportion of academics with PhDs, they are also increasing that proportion more quickly than post-92s (62.7 per cent, up from 60.4 per cent five years earlier, compared with 29 per cent, up from .6 per cent over the same period).
Some warn that this could affect the allocation of research funding.
Pam Tatlow, chief executive of the Million+ group of new universities, argued that the differing qualification levels were down to the more professionally orientated courses in post-92s, which require staff with "practitioner and professional expertise".
She added: "It has always been a bone of contention when Higher Education Innovation Fund or other research-funding formulas require universities to count staff solely on the basis of the highest qualification level without taking into account other qualifications or practitioner experience.
"That is actually a distortion because academic staff can be highly qualified in their field and recruited from industry or elsewhere, but do not necessarily have doctorates: of course, doctorates give no indication as to how well anyone performs in teaching."
Wendy Piatt, director general of the Russell Group of larger research-intensive universities, said: "The vast majority of (our) academics...have doctorates. There may be some slight variation according to discipline, but academics without a doctorate would be very much in a tiny minority.
"This has been the case at Russell Group universities for many years. Providing a first-class teaching and learning experience is vitally important to our universities."