What do a Madonna concert and a banking crisis have in common? Not much, you might think. But, as I sat through an excruciating performance of "Borderline" in Wembley Stadium recently, I realised that Madonna and mammon go together rather well. The common link is trust (or its loss).
I went to Wembley with our friends the Greens, who had purchased tickets for the Sticky and Sweet tour many months ago, but whose offspring had become a little sickly and sour at the very last minute. My wife and I stood in.
The tickets cost £160 each (yes, you read that correctly) even though the best way of seeing Madonna from our vantage point in the stadium would have been via the Hubble telescope.
The sound system was appalling. We could hear a thumping bass line and a few notes, with suspect intonation, from Madge herself but, beyond that, there really wasn't much to enjoy.
A video of abused people from the poorer parts of the world was shown halfway through the concert, perhaps as a reminder that, next time, we should give our money to charity rather than to the Queen of Pop.
The low point, though, was surely the arrival on stage of a group of musicians for what Madonna's website describes as the "gypsy" version of "La Isla Bonita". For a moment, I thought they were a Slobodan Milosevic tribute band.
Maybe Madonna thought everyone was having a fun time. My impression, though, was that this was a poorly conceived performance which managed only to cash in on people's trust.
Madonna's brand image is so strong that, in the eyes of her fans, she can do no wrong. People were prepared to fork out their hard-earned cash because, being fans, they think she will always deliver a quality show. If, though, everyone believes that, perhaps the performance needs only to be mediocre.
For me, the Madonna experience was an example of a market failure. The seller of the product may know something about its quality.
The buyer of the product, though, has to take its quality on trust simply because it's not possible to inspect the potential purchase before parting with one's cash.
Of course, it's always worth reading the views of critics (they exist in part because markets do indeed fail) but, as there was only the one concert at Wembley, you'd have to draw conclusions from her performance at other venues.
On the night, some people walked out but, as the show was costing punters around £1.50 a minute, the majority presumably thought they should hang around.
This issue of trust is a problem across a wide range of markets. Information failures can destroy markets remarkably quickly. Financial markets, in particular, rely on trust.
Indeed, those familiar with the banking system know that it depends entirely on trust: no bank could repay all its depositors in one day because the money simply doesn't exist (which is one reason why, when the run started, Northern Rock was such a disaster).
For the most part, trust is maintained but, once in a while, things go horribly wrong, perhaps because those who were trusted abused their positions. And, as trust disappears, once-respected brands become vulnerable. Madonna, be warned.
Each time there's a rescue, in some cases via the use of public funds, markets rally in the hope that the bad news has been dealt with. After Northern Rock, markets picked up in the hope that a line could be drawn under the UK's problems.
A similar bounce took place following the absorption of Bear Stearns into JP Morgan Chase earlier in the year. Then there was the injection of funds from abroad.
Sovereign wealth funds were treated like the Seventh Cavalry, supplying much-needed capital to shore up the western banking system.
Some of those funds, though, may now be regretting their earlier largesse, given the subsequent further losses incurred by shareholders as many banks' share prices have continued their precipitous decline.
The breakdown of trust within the banking system relates to five factors. First, the assets which banks have lent against — notably housing — have been falling in value.
Second, many banks have not only lent directly to households but have also purchased so-called asset-backed securities — effectively second-hand loans — which they can no longer offload to others.
Third, some banks have bet that these securities, having fallen so far in value, must bounce, forgetting that a 90% drop can still be followed by a further 100% decline from the new, lower, value. Fourth, banks no longer trust each other, so the loans made within the interbank market have dried up, and interbank interest rates remain high relative to policy rates.
Fifth, governments, fearing the political fall-out, are reluctant to use taxpayers' money to bail out institutions which have been abusing trust for too long already.
That reluctance, in turn, has made it more difficult to arrange takeovers. After all, who knows what will be discovered upon the opening of a financial Pandora's Box?
As trust has ebbed away, so the banking system as a whole has begun to look remarkably fragile. No one bank knows for sure what losses other banks are harbouring. This affects all of us.
Over the past 12 months, banks have been squirrelling away cash and, where possible, quietly nursing their losses. No longer do they wish to lend with greedy abandon.
Credit availability has dried up, house prices have fallen and, as fears of recession have risen, so too have stock markets.
Things are likely to get quite a bit worse. As recession bites, so banks will become even more cautious. Further lending cutbacks, though, will magnify the economic downswing and reduce the impact of interest rate cuts from the Federal Reserve, Bank of England and others.
This is, potentially, a market failure on the grandest of scales. The effective nationalisation of Fannie Mae and Freddie Mac was a big, if largely expected, event, but we're not yet out of the woods.
Ask policymakers in Sweden — who ended up nationalising almost their entire banking system in the early 1990s — or in Japan — where, year after year, taxpayers' money was used to prop up a banking system that was near enough bust.
Still, at least some people are making money. Maybe if the banking crisis gets that much worse, the financial markets can turn to Madonna.
The Material Girl isn't short of a few dollars.
Perhaps she could buy a bank or two as a contribution to safeguarding the world's financial system.
Stephen King is managing director of economics at HSBC