Conflicts of interest are sometimes in the eye of the beholder. Yet to critics of the US Federal Reserve system the fact that Jamie Dimon is still sitting on the board of the New York Fed looks an open and shut case. JPMorgan Chase recently lost at least $3bn in derivatives trades that went sour. There are obvious questions about whether the bank’s supervisors were asleep at the wheel.

Even Tim Geithner, who is not known as a scourge of Wall Street, wonders if there is a “perception” problem. He has a point. You do not have to agree that the Fed’s governance structure amounts to the “fox guarding the henhouse” – as its toughest critics maintain – to accept that appearances are critical to central banks.

Yet it is also important to underline what this is not about. Mr Dimon has not been accused of wrongdoing, or of any ethical breaches. JPMorgan lost money because it made a foolish bet. Mr Dimon may have been lax in his own oversight. But it is the bank’s owners, rather than the US taxpayer, that will take the losses.