It's strange to think that "Wag" - the acronym for footballers' wives and girlfriends - entered the Oxford English Dictionary only last year. Already Wags seem as traditionally English a concept as out-of-town supermarkets or chicken vindaloo. Yet they first penetrated public consciousness only in 2006 when they accompanied their husbands to the World Cup in Germany and got themselves photographed tanned orange, drunk and brandishing shopping bags while dancing on bar tables in Baden-Baden.

This week the Wags must be quaking in their Jimmy Choos. Lord Triesman, the Football Association's chairman, estimated English football's total debt at £3bn. He wants - dread words - a salary cap. Liverpool have delayed building their new stadium. Manchester United's sponsor, AIG, has, in effect, been nationalised. Could the credit crunch do to Wags what it did to Lehman Brothers (NYSE: LEH - News) ?

Waggery is one of the oldest professions. Since the rules of football were codified in 1863 or even before then, certain women have been strangely attracted to footballers. The Dutch writer, Jan Mulder, recalls in Hard Gras, a Dutch football journal, that, as centre-forward for Anderlecht in Brussels in the 1960s, he once found himself sitting in a taxi next to Catherine Deneuve when he spotted that she had removed her panties. Nothing in life had prepared him for this moment, so he pretended not to notice and did nothing. Another night, in a restaurant toilet, he fended off the advances of the dancer Rudolf Nureyev. Mulder recalls: "Well, the toilet was too small for us both. He was so insulted. How should I have known? I was new to Brussels. Nureyev staggered into the restaurant and shouted that it was a disgrace. Later we made up and ate steak béarnaise together."

Waggery exists in other sports too. My wife, who once came along as a Wag to the writers' football world cup, has written a book on adultery, a fact that never fails to amuse my so-called friends. In it (Lust in Translation, Penguin) she documents the mating habits of professional baseball players. Apparently their Wags are so pathetically grateful when allowed to join their husbands on road trips that they accept being banned from places such as the back of aircraft and hotel bars where the players prefer to meet the women that Private Eye magazine defines as Shags ("unofficial girlfriends whose numbers appear on footballers' mobile phones").

In Britain, where the Premier League is a sort of working-class mirror universe of the City of London, Wags are best understood as the working-class equivalents of City wives. Historically, the City and the football were the two pools where women who were not keen on working for a living could catch a youngish millionaire. It always was a tough career: John Lanchester recently charted the lifecycle of the City wife, from catch through happiness to renovation of vicarage in distant village with the children while husband maintains a pied-à-terre in London to ousting by younger version of self, to divorce settlement. But now the City appears fished out. Football and its Wags, however, will be just fine.

In Germany recently, Warren Buffett suggested why. Giving a talk to some investors, he asked them what might be the criteria for deciding whether or not to buy a company. Traditionally, the first criterion is a strong balance sheet. But Buffett only put that in third place. His second criterion was a good management team. In first place, he put brand. This is where English football is unbeatable. Clubs such as Liverpool and Newcastle have been building their brands since the 19th century. However humungous their debts, these clubs never fold. Stefan Szymanski, economics professor at Cass Business School in London, says: "There is a long line of rich people queueing up to take over the clubs' liabilities. These individuals are football-crazy and they are brought up on English football."

Szymanski notes that, while dozens of English clubs have entered insolvency since 1992, they still exist. It seems that, whereas the world can live without any single bank, it cannot live without Bournemouth AFC, let alone Chelsea. Even a depression might not decimate clubs, adds Szymanski. "The 1930s was something of a boom period for English football."

The Wags might be about to collapse beneath a bar table but not beneath the weight of their own contradictions. This year may even go down as the year they were crowned on red velvet thrones à la David and Victoria Beckham at their 1999 wedding. Studies of happiness show that what makes people happy is not absolute wealth but having more than others. The City wife's pain is the Wag's pleasure.

But Wags beware. Once a sideshow, they could become the only game in town, except for the National Lottery - which has already created well over 2,000 millionaires. The shrinking of opportunities for wannabe millionaires' partners will expose Wags to increased competition. Short careers could get even shorter as the British middle classes and foreign imports swarm to entice their husbands. Perhaps the Wags should diversify out of sunglasses and salt away some of their assets in stocks. On second thought, perhaps not.

simonkuper-ft@hotmail.com