Sporting defeats are often attended by hyperbolic and ill-thought out outpourings of woe, and England's ignominious defeat to Croatia last week has unleashed a predictable torrent of soul-searching and doom-mongering. Perhaps the silliest element of this torrent, though, has been the claims that England's failure to qualify for Euro 2008 will cost the UK economy £1 billion.
Indeed, whilst many newspapers quoted the verdict of the Centre for Economic and Business Research that the economy would take a £1 billion hit, the Daily Mail told us that the loss would be as much as £1.5 billion, with the Telegraph pushing out the boat to predict a loss of £2 billion.
These figures are arrived at by thinking about all the things that people now won't be doing because England won't be playing in Euro 2008.
Fewer people will be watching football matches in pubs, and so publican's and brewer's takings are expected to be down by £285 million. The replica shirt market will be hit, with sales of the England kit down by as much as £100 million. People won't do so much gambling on football, so betting companies will take a hit as well.
It's not difficult to think of the companies that stand to lose from England's defeat, and so adding their losses together to arrive at an overall economic loss might initially seem like a reasonably plausible procedure.
A moment's thought, though, reveals that it is absurd to think that the 'cost to the economy' can be arrived at through adding up the cost to brewers, publicans, bookies and sportswear makers. For this is the 'cost to the economy' only if the money that people would have spent on booze and betting were somehow now completely to disappear.
But it is a reasonable prediction that people won't burn the money that they would have spent whilst watching England struggle to a 1-1 draw against Switzerland in some imagined alternative future. Neither will they stuff the money into their mattresses, or use it as bedding for their household pets. No.
They'll either spend it on other items of consumption or they'll invest it.
Rather than being lost to the economy, the money will just be used in some other way. And so it's ridiculous to come up with some notional 'cost to the economy' of England's defeat only by adding up all the economic losses, without thinking of all the consequential economic gains.
This sort of error is very common, and comes up all over the place. It's the error of assuming that 'all other things will remain equal' when a second's thought would show that other things will not remain equal at all.
It's true that the economy would take a big hit if we simply took away people's spending on Umbro shirts, big-screen TVs, pints of lager, and all the other paraphernalia of football watching. But that's not what's going to happen.
Instead, people are going to do other things with their time and money instead.
Many lazy stories are written around spurious claims about the 'cost to the economy' of something or other. A lot of crazy figures are plucked out of a hat and then paraded for our delectation by a gullible media.
For example, the CBI claimed in August that instituting a new Bank Holiday would cost the economy 'up to six billion pounds' a year. And the government's Foresight report on obesity claimed that by 2050 obese people would cost the economy a truly gigantic £45 billion every year.
But, the CBI's figure looked only at lost work days rather than thinking about all the extra expenditure that people could do on their extra day off, let alone the extra productivity that might emerge if people were able to recharge their batteries rather than working through without a break from the end of August to Christmas. In the same way, the figure on obesity simply added the costs of time off work and ill health due to excessive weight, whilst ignoring the effect on Britain's fast-food retailers that would be entailed by a radical change in diet.
The truth is that most claims about 'cost to the economy' just don't stand up.
Many changes have unintended consequences, and most stories about overall economic cost make only the most perfunctory effort to think about what those other consequences might be.
Here's a prediction, though: I hereby claim that the economy will be no worse off for England's defeat to Croatia. We'll spend less on betting and booze, but we'll instead spend that money on something more useful instead whether on capital goods like home improvements or consumption goods like restaurant meals or trips to the cinema.
Instead of 50-60,000 English fans making the pilgrimage to follow their team in Austria and Switzerland, most of them will instead take one fewer holiday and spend their money at home instead. With England out of the tournament, the nation will be much less likely to skive off work to go home to watch the footie, and we'll collectively spend more of our time at work actually working instead of hanging out by the proverbial water cooler and exchanging withering verdicts on Steve McClaren's tactical naivety.
Brewers and bookies will take a hit, but all other things in the economy will not remain equal, and one industry's loss will very likely be another's gain.
There is good reason to bewail the embarrassment of last week's inglorious footballing collapse. But the loss is primarily to national pride, rather than the headline-grabbing blather about 'the cost to the economy'.