Academics are contributing to a decline in textbook buying, according to a publishers' survey, because they are reluctant to ask cash-strapped students to pay for course materials.
The research concludes that students would rather spend money on clothes and entertainment than books required for their studies. But another reason for declining sales is thought to be lecturers' attitudes.
The findings come amid warnings that the closure of a Waterstone's bookshop on Brunel University's campus could be the first of many across the higher education sector.
Philip Carpenter, academic and science books director for Blackwell Publishing, and a spokesman for the Publishers' Association, who carried out the research, said: "Our study found that there has been a decline in textbook sales for the past few years."
The research, based on interviews with lecturers and students, found that a lecturer's strong recommendation would lead 80 per cent of students to buy a book.
The academic book market is still worth more than £150 million a year, but no growth is expected despite increasing student numbers.
Dominic Knight, managing director of Palgrave Macmillan publishers, said that the problem was partly caused by a new reluctance among lecturers to ask students to pay for their course materials.
He said: "Students do value textbooks, but because lecturers are concerned about students' pockets, they have a sense of embarrassment about the strength of their recommendations. The research found that students like a strong steer from lecturers about which books to buy."
Mr Knight said: "Students spend less on textbooks than they do on entertainment, so it's a matter of where you put beer and jeans in a list of priorities."
Waterstone's is closing its Brunel store - one of 34 campus outlets - in January after it was deemed "unviable".
A Waterstone's spokesman said: "This was a specific closure, and there are no plans to shut any more academic branches. We will be expanding our range of academic titles at local branches so students have somewhere to purchase textbooks."
But Paula Burnett, a senior English lecturer at Brunel, said: "Students will buy the books they are told they absolutely have to buy, but they can't afford to read as much as we'd hope."
"I don't think it's an issue of laziness, it comes down to finance. If Waterstone's says that its shop on the campus is not viable, then I find it hard to believe that it is a problem unique to our campus."
The study by the Publishers' Association highlights widespread frustration among lecturers that students do not read as much or as widely as they should.
They felt that students rely too heavily on lecture handouts and on the web - sources that, they say, lack the authority and breadth of books.
Lecturers said that a growing number of students were taking a consumer-like approach to their time at university.
Students were increasingly conscious of grades and results, said the lecturers surveyed, who expressed disappointment that students did not take more academic interest in their subjects.
They reported that the incidence of plagiarism is rising.
Despite students' increasingly consumer-savvy approach, when asked how they decide which resources to use, they look first to their lecturers - such recommendation being by far the most powerful influence on students.
More than 80 per cent of students who received a strong textbook recommendation from their lecturers purchased the book, compared with 30 per cent of those who received a weak recommendation.