Eliot Spitzer, the New York attorney general, may be a politician on the make; he may fire from the hip; he may dispense pretty rough justice. But his brash style of scalp-hunting has been far more effective in exposing and curbing company abuses and forcing them into better behaviour than the ponderous approach of conventional regulators.
His latest target is the US insurance industry. Spitzer has filed a lawsuit against Marsh & McLennan, the world's biggest insurance broker, accusing it of corruption and anti-competitive practices. In a nutshell, Marsh stands accused of accepting incentive commissions (or bribes, depending on your point of view) to push business towards a particular insurance company.
Marsh is well known here, not just for its large insurance operations in London, but also because it owns the actuaries Mercer Human Resource Consulting, which advise hundreds of British pension funds, as well as the corporate private eyes at Kroll.
It is also a US company that likes to decorate its board with a British Tory peer. Lord Lang, the former trade and industry secretary in the Major government, has been a non-executive director since 1997. Over the past two years, Spitzer has scrutinised large tracts of the American business landscape. First came the investment banks, which were forced to pay billions of dollars to settle allegations that they published biased investment research to keep their big corporate clients happy.
Then came the mutual funds, which again paid vast amounts to settle allegations that they allowed favoured clients to trade to the detriment of their ordinary customers - the millions of Mom and Pop investors of America.
Then came a swipe at the drugs industry.
Our very own GlaxoSmithKline was accused of misleading doctors over the dangers of its antidepressant Paxil, which could lead to a higher risk of suicide in adolescents. Glaxo denied the charges but agreed to pay a $2.5m (£1.4m) settlement. More significantly, it announced plans to publish all clinical trial results in future.
Spitzer is fighting a legal battle against Dick Grasso, the former chairman of the New York Stock Exchange, and seeking the return of $100m (£55m) from $139.5m in allegedly ill-gotten rewards. He describes the exchange as rife with conflicts of interest and double-dealing.
Spitzer, who has political ambitions to become governor of New York and ultimately perhaps the president of America, has put conventional regulators on both sides of the Atlantic to shame.
He has shown that a few incriminating e-mails and a convincing whistle-blower are all that is required to bring the most powerful corporations to heel.
Surveying the mangled trolley-wreck that is J Sainsbury today, it's hard to believe that it was only 12 years ago that the supermarket group was the biggest and most profitable in the country.
It is easy and right to blame Sir Peter Davis, who stepped down as chief executive in June this year, for many of its recent troubles. But the real problem stems from its being a family business - the Sainsburys and their charitable trusts still own 36 per cent or so.
A worthy but misplaced sense of family duty made David Sainsbury, now Lord Sainsbury of Turville, the science minister, take over in 1992 as chief executive from his cousin John Sainsbury, Lord Sainsbury of Preston Candover. John, a details-obsessed dictator, was unlike David, a gentle consensualist more interested in philanthropy than beans and tills. Meanwhile, the family shareholding stopped the minority shareholders from having the clout to call management to account. And the arm's-length trust through which David now holds his shares has added to the lack of accountability. If Sainsbury's had been as successful as Tesco in terms of profits growth over the past 12 years, the family holding would be worth more than £10bn. As it is, they are down to their last £1.7bn.
He who pays the piper calls the tune, as employers hiring actuaries to advise on their pension schemes know very well. The actuary who wins the contract is often the one who can justify the lowest employer contributions while conveying the most positive picture to pension-fund members and trustees.
A new report from Mercer and Hewitt Bacon & Woodrow suggests that much of the usual language of actuaries is meaningless. The description of a pension fund as "100-per-cent funded on an ongoing basis" might sound reassuring, but can in fact be applied to one that is insolvent.
There are more methodologies in actuarial science than pensioners in Eastbourne. Trustees, please take note.
Patrick Hosking is investment editor of the Times