Eight years ago, I published a novel called A Vicious Circle satirising the corruption of the literary world. It caused a scandal which, perhaps naively, I had not anticipated, and even received a libel threat from one critic, that got it dropped by Penguin. Yet there was not a single thing that my imaginary critic, the louche and cynical Ivo Sponge, told his protégée about how to review that had not been said to me in real life, by a variety of critics and editors. When I first became a published novelist in 1990, I had not realised just how mired with politics and corruption the reviewing business is, but, like many readers I had often been puzzled by the way unreadable books were made wildly fashionable, while good books discovered browsing in bookshops were neglected or misrepresented. It was only when I began to review myself, and read proofs before the critics got hold of them, that I became incensed.

What should a review do; and who is it for? The first part seems straightforward: It should tell you what a book is about, how its contents are revealed, and whether, in the opinion of the critic, it is worth reading. But it is in addressing the second part of the question that corruption creeps in. Obviously, as a piece of journalism, a review is written for the literary editor who commissioned it. From the editor’s point of view, it is there to help sell the newspaper, which means it must, ideally, attract attention just like any other piece of journalism. It is a form of news, informing people who may not read the book what it is about. It is also a form of advertising, for worse than a bad review is no review at all. Furthermore, a review must contain some kind of aesthetic judgement which should have nothing to do with its hype, newsworthiness or author photograph. All of these demands can and do come into conflict with each other.

Scott Pack, the buying manager for Waterstones who recently complained in The Bookseller that reviews were failing to “inspire reading”, lives at the commercial end of the reviewer’s audience; self-appointed guardians of the cultural elite at the other. Reviewers, meanwhile, have their own agenda. They may begin out of a pure and selfless love of reading, but they soon find themselves tempted to show off in a gladiatorial arena in which their own judgement, championship, style and power become paramount. A really savage attack on someone’s book will always raise your own status as a critic because it makes people fear you; on the other hand, if you write something nice and quotable, then authors and publishers love you. The audience that gets ignored is therefore the one which should come first: the reader.

Of course, tastes differ. Yet the judgement that dictates whether or not a book is reviewed is so often dictated by matters of name and fame, rather than individual quality. This is what literary editors are paid to discover, yet few seem to try. A really outstanding book such as Lionel Shriver’s We Need to Talk About Kevin, was reviewed in The Independent, and its Sunday sister, by The Times, the TLS and the New Statesman: but at the time of writing this, most other papers still haven’t noticed its existence. It has just won the 2005 Orange Prize.

Readers may be shrewd enough to smell a rat when the critic has, say, written biographies of the same subject, and has a vehement reaction for or against, but often you need to know a bit more. Andrey Kurkov’s review in The Guardian of Marina Lewycka’s debut, A Short History of Tractors is a recent case in point. He attacked her dark comedy of expatriate Ukranian life by complaining, “this novel will not leave the reader any the wiser about the Ukranian community in England. What we are offered is the banal tale of a Ukranian woman who enters the UK on a tourist visa and who is prepared to go to any lengths to remain in the country.” Wrong: the tale is about how two sisters fight back against the woman who has seduced their elderly father, about their parents’ sufferings under Stalin and how they have affected the family. It is not intended as a portrait of an expatriate community. Sneering at her characters, Kurkov complained that “Just about everyone portrayed in it inspires sympathy…except the Ukranians, legal and illegal.” As every major character in the novel is Ukranian, this suggests a total absence of attention. Or, could it be…sheer envy, because as a Ukranian novelist himself, he wasn’t getting the serialisation on Woman’s Hour that turned Lewycka’s novel into a hit?

The general reader might notice, meanwhile, that a book by a Guardian journalist is always greeted with glowing notices in their home paper, just as a book by a Sunday Times journalist is usually panned in the Sunday Times books section. The job of a literary editor is a hugely political one. Spleen and envy, friendship and flirtation all come into play in the choice of critic, even before he or she has read a word of a new book. No editor is fool enough to direct a critic’s response, but most will have a “general chat” about how an invited critic feels about the author first. It is hard not to suspect that the response is being guided one way or the other in the course of this, on at least some papers.

The reader, who can divine little or nothing of this, is therefore conned both ways. He or she can be fooled into thinking that X’s book is an abomination which should shame the barely literate, or, alternatively, that it is the hottest read ever. Women critics tend to be scrupulously fair-minded – which may perhaps account for their being outnumbered by around 10 -1 on newspapers and magazines - but not so the opposite sex, busily promoting their best mates or demoting their ex-lovers. Even when untainted by personal relationships, the prejudice can be jaw-dropping. For instance, Robert McCrum, literary editor of the Observer, repeatedly poured withering scorn on Linda Grant’s second novel, When I Lived in Modern Times, which unlike his favourite, Zadie Smith’s White Teeth, went on to win the Orange Prize. Some montchs later, he revealed in his column that he had never bothered to read Grant’s novel.

Men review, and are reviewed, differently. Nowhere is this more evident than in the treatment of Ian McEwen’s latest novel, Saturday. It would have been very interesting to have had the female opinion on, say, the portrait of a marriage in which the hero’s wife is always ready and willing for sex twice a day, despite never having a conversation with her husband, and in which the hero’s daughter deflects the violent intentions of her would-be rapist by reciting Matthew Arnold’s poem, Dover Beach, while stark naked. No such opinion was sought in the rapturous applause that greeted the novel, and it was not until the Irish writer, John Banville, wrote a long and devastating critique of Saturday in The New York Review of Books that the absurdity of the plot was noted.

You may well decide that McEwen is such an interesting writer that it doesn’t matter if his plots are melodramatic tosh. It does, however, matter that this wasn’t pointed out by the British press. Over and over again, when researching this piece, McEwen’s name came up among women critics as someone who is reviewed only by his “peers”: that is, men. I am certain that this is not at his own request, but it does no favours to the reader, or the culture on which he aims to leave his mark. It is equally predictable that Julian Barnes, William Boyd and Philip Roth will also be strictly for the boys’ club this year, despite their many female readers. Women only get to review books by other women – or, once in a while, gay men, who, strangely, are also the only men to regularly review books by women.

Few literary editors, meanwhile, have sufficient probity to check whether author and critic have any connection with each other as friends, or through agents and publishers. This, standard practice on The New York Times, (and, I may add, on the London Times) is the opposite of what I called in A Vicious Circle, the “fear or favour market.” There are only about 100 regular reviewers for the national press, and sooner or later everyone meets. Many critics, myself included, pass on a book they dislike by a friend for fear of giving pain; the less scrupulous will give it a good review, or a bad one because they want to be part of a particular clique or claque. No other profession suffers from this nightmare of proximity, which causes a thousand compromises, as well as limitless opportunities for revenge. Worse, from the reader’s perspective, is when an author is the beneficiary of what is known as “log-rolling”: you praise my book and in due course I’ll praise yours or make sure my friends do. It is a fair guess that about 80% of critics asked to recommend their choice of summer book or a Book of the Year will choose at least one by their pals.

Herein lies the rub. Writers often do admire each other’s work, and may, like the late Penelope Fitzgerald or Margaret Attwood, express their perception of its quality in an illuminating way. But the constant reciprocal in-fighting and in-loving is at the heart of why our books pages are so unreliable, and the person who loses out is the reader.

I suspect that the growth of weblogs such as book.slut, and reading groups (including the wonderful Richard & Judy show) springs from the distrust many readers feel for critics, and the feeling that we are not being helped to find what is good rather than be spectators in an arcane cultural game. Passionate amateurs can’t be faulted for honesty, so why don’t literary editors look at amazon’s Top 100 readers’ reviews, some of which are strikingly well-written, by wholly unknown enthusiasts?

Everyone, however, complains about the lack of review space and coverage. Individual reviews have been cut by over 50%, and there now seems to be nothing in between what the writer Joan Smith calls “telegrams to the reader” and the inordinately long essays in the TLS or LRB. Nothing is going to change unless more readers make their voices heard. We no longer live in a world in which the good will somehow be discovered irrespective of critics, because so many books are given no space or time in which to build a readership. The supermarkets and chain booksellers who refuse to stock books without big budgets and big bribes are the chief villains, but reviewers and editors also bear real responsibility for failing to sort the wheat from the chaff. I wish I could say that the world I satirised almost a decade ago has changed for the better. Instead, it has got worse.

Amanda Craig’s novel, A Vicious Circle, was published by 4th Estate, and its critic Ivo Sponge reappears in her most recent book, Love in Idleness. She reviews for The Times, The New Statesman and The Independent on Sunday, and she is one of amazon’s top 50 reviewers.