Who needs sex when you can go shopping?

It was Willy Russell's Shirley Valentine who first compared sex to shopping - seeing both as overrated, involving an awful lot of pushing and shoving and producing very little in the end.

According to a new book, she was right. Sex and supermarkets are inextricably linked, says Stephen Brown, professor of retailing at the University of Ulster and one of the authors of Romancing the Market. Both activities are apparently fraught. Frustration, disappointment and regret are just as common as ecstasy, bliss and satisfaction - both in bed and on the high street.

The similarities between the two activities come down to men and women's different attitudes, he says. "Men, to put it bluntly, adopt a wham-bam, thank-you-ma'am approach to shopping. They know what they want, they expect to get it and they are in and out as quickly as possible." Women, on the other hand, engage in an impossible search for the retailing equivalent of Mr Right. This involves carefully examining what's on offer before settling for their preferred choice, which is usually the least worst option.

"As far as men are concerned," says Professor Brown, "women take far too long. And as far as women are concerned, men don't take enough time to do it properly."

He says that women are prone to "occasional wild, reckless, impulsive, impassioned flings with products that make then go weak at the knees and which may never be unwrapped or worn". Meanwhile men's "love 'em and leave 'em" approach only alters when they encounter something that means a lot to them - such as compact discs, computer games or books.

The difference in shopping style between the sexes means that it is "far from being a form of foreplay [but]... fraught with danger".

A study of undergraduate students found that many went shopping as an opportunity to "ogle members of the opposite sex", and also found shopping malls a less pressurised place to meet people than the traditional party, pub or disco.

"Certainly many women seem to take the opportunity to get dressed up or try to look their best when they go shopping, just in case they meet the man of their dreams," says Professor Brown.

Yet although the erotic potential is great, it can also prove deeply unsatisfying. According to the research, shopping focuses on one's fear of physical imperfections and whether one can match up. Unfortunately, there's usually someone much better looking, much better dressed and financially, physically or matrimonially better off than ourselves just ahead of us in the queue. "These beautiful people make everyone else feel like a fat, frumpy failure by invidious comparison," Professor Brown says.

Sudden identity crises come to a climax in the changing room, where harsh lighting and wall-to-wall mirrors contrive to condemn all but the most egomaniacal to profound paroxysms of self-loathing. And it gets worse - "Above and beyond putting one's pale, pustular and podgy physique on painful display," adds Professor Brown, "consumer goods themselves can castrate, frustrate or emasculate the shopping experience."

For men buying certain categories of goods with sexual or narcissistic connotations, such as moisturisers and toiletries, shopping can prove excruciatingly embarrassing, though not as mortifying as standing outside female changing rooms (which are unfailingly situated in the lingerie section) while their partners wrestle and ruminate inside.

"Shopping, like sex, is often far from satisfactory," Professor Brown concludes, saying that it is both physically frustrating when imperfections are exposed in changing rooms but also metaphorically frustrating on account of all that unrequited love for must-have- can't-have merchandise.

"Anguish, bitterness, betrayal, pain, remorse, regret, despair, self- abasement - in fact all the symptoms of heartache - are on agonising display," he says. Sounds suspiciously like a particularly neurotic episode of Ally McBeal. Expect the sex 'n' shopping episode on a screen near you very soon.

`Romancing the Market', edited by Stephen Brown, Anne Marie Doherty and Bill Clarke, is published by Routledge at pounds 19.99