Men can expect a massive pay boost during the lifetime if they get a first class honours degree from university - but women won’t earn an extra penny.

These are the startling findings from new research from the Centre for Economic Performance, based at the London School of Economics, published today.

The figures, from a study of more than 2,600 graduates from the LSE between 2005 and 2010, show that - on average - a student with a first-class degree earns three per cent more than those with a 2:1.  However, a gender breakdown shows that this means six per cent extra (or £1,780 a year) extra for men and zilch for women.

Over the course of a lifetime, this would be worth around £71,000 more for men - if their salary increases at the same rate.

The authors of the research, Andy Feng and Georg Gratz, admit they are baffled by its findings. “The difference between monetary gains for men and women is a puzzle,” they say.

One theory they put forward is that men are more likely to ask for more money or be given a higher wage offer in the first place by employers. “We honestly don’t know,” they add.

The research goes on to show that there is an even bigger gap in earnings between those gaining a 2:1 and those getting a 2:2 degree - the difference is worth about seven per cent in higher wages or the equivalent of £2,040 a year. There is no discernible gender gap in pay here, though.

“We find sizeable and significant effects for upper second degrees and positive but smaller effects for first class degrees on wages - we find that a first class and upper second are worth around £1,000 and £2,040 per annum respectively,” says the report.

The authors point out that those getting the £1,780 annual bonus for a first can be benefiting simply because they get one extra mark than those with a 2:1. The criteria for a first-class degree pass from the LSE is five scores of 70 per cent or more in five of a student’s nine papers. Scoring 69 per cent in the fifth paper would not cut the mustard.

“Our study is probably the best evidence available that exam results matter but there’s a lot more work to be done in understanding what drives the gender split,” the authors conclude.

The say “a sizeable fraction” of employers use degree classifications as the main indicator when assessing whether to hire someone - 75 per cent insisted on an upper second as the minimum entry requirement in 2012 compared to just 52 per cent in 2004.