One of the bitterest and most time-worn debates in student union bars up and down the country is resolved today as academic research confirms that in financial terms at least, arts degrees are a complete waste of time.

Getting through university boosts student's earnings by 25%, on a weighted average, or £220,000 over their lifetime, according to Professor Ian Walker of Warwick University - but if they study Proust or the peasants' revolt instead of anatomy or contract law, those gains are likely to be completely wiped out.

The government is about to allow universities to charge students up to £3,000 a year for their degrees, arguing that it is a small price to pay compared to the financial rewards graduates reap later in life. But Prof Walker's research shows there are sharp variations in returns according to which subject a student takes.

Law, medicine and economics or business are the most lucrative choices, making their average earnings 25% higher, according to the article, published in the office for national statistics' monthly journal today. Scientists get 10-15% extra.

At the bottom of the list are arts subjects, which make only a "small" difference to earnings - a small negative one, in fact. Just ahead are degrees in education - which leave hard-pressed teachers an average of 5% better off a year than if they had left school at 18.

"It's hard to resist the conclusion that what students learn does matter a lot; and some subject areas give more modest financial returns than others," Prof Walker said. As an economist, he was quick to point out that students might gain non-financial returns from arts degrees: "Studying economics might be very dull, for example, and studying post-modernism might be a lot of fun."

The financial benefits of a degree could also begin to dwindle as access to higher education widens, according to the report. Prof Walker found some evidence that graduates who left university in the 1990s are seeing slightly lower returns than those who graduated in the 1980s and before.