An over-supply of graduates in Britain means that having a degree is no longer a guaranteed ticket to a lifetime of higher earnings.
Research carried out at Swansea University has found that the earnings gap between graduates and non-graduates is rapidly eroding and the relative wages of graduates is falling.
The average university graduate will now earn only £140,000 more than their a non-graduate, a huge fall on the government's estimate of £400,000 used to justify the introduction of university tuition fees.
But the size of the earnings difference can vary enormously between graduates in different disciplines.
Maths, computing and engineering graduates can expect to earn £222,000 more during their lifetimes than non-gradates.
But in arts and humanities subjects, too many graduates competing for too few jobs means that male arts graduates can expect to earn just £22,000 more than non-graduates over the course of their working lives.
And according to Professor Peter Sloane and Nigel O'Leary, who carried out the research, this means that male arts graduates who studying in England or Wales could actually end up worse off after annual tuition fees of £3,000 and loss of earnings are taken into account.
Mature students are even less likely to profit from going to university because of their greater loss of income, the report said.
The findings will come as a blow to Britain's graduates, nine out of ten of whom believe that the money they spend on their education is a good investment in their future and half of whom choose to go to university because they believe it will improve their job prospects.
"There has been an increase in the demand for graduate jobs, but the increase in supply is outstripping the increase in demand," Nigel O'Leary said. "There is quite a lot of evidence that graduate earnings are declining."