The costs imposed by the financial crises that hit western economies in 2007 have been enormous. UK gross domestic product is nearly a fifth smaller than if long-term pre-crisis growth trends had continued. The costs also include huge rises in public debt. In the UK the increase, as a direct and indirect result of the crisis, will be close to 50 per cent of GDP.

This is the fourth most costly fiscal event of the past 225 years, after the wars with post-revolutionary France and the first and second world wars. Mismanaged finance imposes fiscal costs that are not far short of world wars.

This is the background against which to judge predictable complaints that the post-crisis regulatory regime is too onerous and will prevent banks supporting the economy as well as they did when creating the crisis. In the UK particularly strong complaints are directed at the plan to ringfence retail banking from other activities. They often come from people connected to banking. But they would complain, wouldn’t they?