Mea culpas are rare these days. In a debate with John Kerry in 2004, President George W. Bush fa­mously could not name a single mistake he had made in his first term. So it is both noteworthy and commend­able that Alan Greenspan, the former US Federal Reserve chairman, fessed up that he had failed to anticipate the financial crisis.

“Those of us who have looked to the self-interest of lending institutions to protect shareholders’ equity (myself especially) are in a state of shocked disbelief,” he said. Mr Greenspan had faith that banks were prudent enough to make sure they were not lending money cheaply to people who could not pay it back. Yet that is what happened. As Mr Greenspan says of securities based on subprime mortgages: “To the most sophisticated investors in the world, they were wrongly viewed as a ‘steal’.”