Throughout the debate on increasing university tuition fees, I have heard no mention of the hidden costs. Here are six of them:

? One unplanned result of the increase is likely to be a significant drop in the participation rate of domestic students in postgraduate studies. As a lecturer with responsibility for admission to a master's programme, I have discovered that most UK students are unwilling to take on additional debt to pay for the degree, even with tuition fees set at "only" ?3,000 a year. What will happen if fees are tripled?

? Another likely outcome is a significant deterioration in student attendance and completion rates. Under our current system, about 90 per cent of British students complete their studies without having to take a break from university, compared with only 66 per cent of US students. Just 3 per cent of students at UK institutions switch between full- and part-time study, compared with 34 per cent in the US. Taking a break to earn money disrupts the continuity of the learning experience and also disturbs learning relationships with classmates. In addition, British degree courses are not designed in a way that makes it easy for students to drop in and out or change their mode of study. If a student leaves their course for a year or two, changes in the curriculum can leave them at a distinct disadvantage when they return.

? We can expect more students to work part-time during their studies - and for more hours per week than they do now. Only 46 per cent of UK students are employed during their undergraduate degrees, for an average of 11 hours a week. In contrast, 73 per cent of US students work part-time, and those who do are employed on average for 21 hours a week. More than one-third of US students fail to complete their degrees, compared with the UK's non-completion rate of only about one-tenth. If higher fees become law, we can expect the non-completion rate here to increase significantly. We may also see a decline in student attendance and performance levels.

ÖйúAƬ

? A rise in the number of part-time employed students (and the hours they work) will make it increasingly difficult for them to complete their group-based and independent studies.

? Since it is estimated that graduates will on average earn about 30 per cent more in their lives than they would without a degree, the cost of their university education will be recovered from the higher taxes they will pay on their income. What then is the point of taxing them additionally to attend university? The total social and economic cost does not add up to improvement.

ÖйúAƬ

? Finally, we hear that David Willetts, the universities and science minister, plans to offer a two-year tuition-fee waiver to 20,000 of the country's poorest students. But why not three years, or four? How are students from poor backgrounds going to afford their final year? There is another problem: just because students do not come from poor backgrounds does not mean they can afford to pay the high costs being proposed for university tuition. Will it be possible for 18-year-old undergraduates to claim for tuition-fee waivers?

Barry Lee Scherer, University of Brighton.