The extraordinary risk-management discipline that developed out of the writings of the University of Chicago's Harry Markowitz in the 1950s produced insights that won several Nobel prizes in economics. It was widely embraced not only by academia but also by a large majority of financial professionals and global regulators.

But in August 2007, the risk-management structure cracked. All the sophisticated mathematics and computer wizardry essentially rested on one central premise: that the enlightened self- interest of owners and managers of financial institutions would lead them to maintain a sufficient buffer against insolvency by actively monitoring their firms' capital and risk positions. For generations, that premise appeared incontestable but, in the summer of 2007, it failed. It is clear that the levels of complexity to which market practitioners, at the height of their euphoria, carried risk-management techniques and risk-product design were too much for even the most sophisticated market players to handle prudently.

Even with the breakdown of self- regulation, the financial system would have held together had the second bulwark against crisis – our regulatory system – functioned effectively. But, under crisis pressure, it too failed. Only a year earlier, the Federal Deposit Insurance Corporation had noted that “more than 99 per cent of all insured institutions met or exceeded the requirements of the highest regulatory capital standards”. US banks are extensively regulated and, even though our largest 10 to 15 banking institutions have had permanently assigned on-site examiners to oversee daily operations, many of these banks still took on toxic assets that brought them to their knees. The UK's heavily praised Financial Services Authority was unable to anticipate and prevent the bank run that threatened Northern Rock. The Basel Committee, representing regulatory authorities from the world's major financial systems, promulgated a set of capital rules that failed to foresee the need that arose in August 2007 for large capital buffers.