On such chances the wheel of history turns. But this time was different: the crisis brought Barack Obama to power close to the beginning of the economic collapse. I (among others) then argued that policy needed to be hugely aggressive. Alas, it was not. I noted on February 4 2009, at the beginning of the new presidency: "Instead of an overwhelming fiscal stimulus, what is emerging is too small, too wasteful and too ill-focused." A week later, I asked: "Has Barack Obama's presidency already failed? In normal times, this would be a ludicrous question. But these are not normal times. They are times of great danger. Today, the new US administration can disown responsibility for its inheritance; tomorrow, it will own it. Today, it can offer solutions; tomorrow it will have become the problem. Today, it is in control of events; tomorrow, events will take control of it. Doing too little is now far riskier than doing too much." This was right.

The direction of policy was not wrong: policymakers - though not all economists - had learnt a great deal from the 1930s. Sensible people knew that aggressive monetary and fiscal expansion was needed, together with reconstruction of the financial sector.

But, as Larry Summers, Mr Obama's chief economic adviser, had said: "When markets overshoot, policymakers must overshoot too". Unfortunately, the administration failed to follow his excellent advice. This has allowed opponents to claim that policy has been ineffective when it has merely been inadequate.