Now a new idea has been proposed by US academics. Listed firms should be required to take out an insurance policy against the possibility that their accounts might be mis-stated. Then the insurance company that writes the policy appoints auditors to oversee the statements and to guard against the risk of a claim.
There are problems with this wheeze. Can insurers can be relied on to perform this role? Who would audit insurers themselves? Would there be a competitive marketplace for this kind of insurance? It's an idea worth further consideration, though. I have seen no debate about it on this side of the Atlantic yet.
A similar conflict of interest may be found at the BBC, where the governors are both regulators and part of the corporation's management. Resolving that problem is at the heart of the review of the BBC's charter.
I've been sitting on a panel that is trying to advise the Government what to do. The panel is chaired - as these things always are nowadays - by Lord Burns. Alan Budd is also a member, though he took a couple of weeks off to deal with David Blunkett. (He asked us to fill in for him in his absence - no favours, chaps, he said, just work a little quicker on my behalf.)
In his book, Greg Dyke says that everyone who goes into the BBC can see clearly that governors can't do both roles, but end up defending the status quo for fear of something worse. Michael Grade is certainly doing a sterling job of clinging on to his two hats. The governors are moving into new premises to emphasise their distance from the management. At the same time, they are getting closer to management decisions to emphasise their involvement in running the business. When I quizzed Grade on this dichotomy at a public seminar, he said I should take over from John Humphrys when he retires (would the nation survive such a crisis?). John and I are consulting our lawyers as to whether this libels me or him.
The Government is about to publish a Green Paper on the options. It's a tricky choice for Tessa Jowell. To make no change would look curious, but any move to cut the governors down to size might be seen as further post-Hutton revenge. Expect some careful drafting.
It is striking that most of the issues raised in the charter review are about television. The big money, of course, is spent on BBC1 and on the so-called digital switchover.
As an intravenous Radio 4 user, my own switchover took place at the end of last year when Father Christmas gave me a digital radio. The effect is miraculous. There are stations whose existence I hadn't previously suspected and a massive improvement in reception. Even Talksport from the Test, with its endless ads from ambulance-chasing compensation solicitors, is almost tolerable.
As I understand it, there are no comparable quality improvements in television's digital change, so what is it all about?
Alan Budd's discovery of a smoking Home Office fax created the opportunity for Ruth Kelly's advancement to the cabinet. As a result, she has jumped into the lead in that younger generation of Labour politicians, leapfrogging David Miliband, who might have expected to have inherited Charles Clarke's seat.
She was for almost three years the minister who oversaw the FSA. In my first three years there, I had five different ministers who threw financial regulation from one to the other like a hot potato. Only Kelly seemed prepared to juggle with it for any length of time. And it didn't get any cooler, what with Equitable Life, split-capital investment trusts and all the other triumphs delivered to us by the industry.
So she's no stranger to controversy, which will be useful in the education sector, where there is a lot of it about. One of her early tests will be the NUT's Easter conference. There is no pleasure to be had from that event, which Charles Clarke snubbed last year, so the four little Kellys may come in for a holiday treat at the end of March.
Nannygate did no harm either to John Gieve, the permanent secretary at the Home Office, who duly got his knighthood in the New Year's honours. The business community did reasonably well, too. Digby Jones got his just desserts. And Bryan Nicholson got a leg up in the pecking order of knighthood. His role in pulling Derek Higgs' chestnuts out of the fire, and making his report just about implementable, has been recognised.