It was to be expected that our present economic traumas would call into question the state of economics. “Why did no one see the crisis coming?”, Queen Elizabeth reportedly asked one practitioner. A seminar at the British Academy tried to answer and the FT has taken up the discussion.
The Queen's question is understandable, given the subject's claims on its own behalf. Ever since modern economics started in the 18th century it has presented itself as a predictive discipline, akin to a natural science. Since the future a year ago included the present slump, it is natural that the failure of the economics profession – with a few exceptions – to foresee the coming collapse should have discredited its scientific pretensions. Economics is revealed to have no more clothes than other social science. One cannot imagine the Queen in, say, nine months' time, asking a leading political scientist: "Why did no one tell me that Labour was going to win the election?" She would understand that this was not a prediction that any political scientist could make with conviction, however much time he had spent studying present and past opinion polls.
Nevertheless, the Queen's question was wrong, because it accepted at face value the predictive claim of economics – a feature that has distinguished it from all other social sciences. Karl Popper produced a famous argument against the possibility of prediction in human affairs: one cannot anticipate a new invention because, if one could, one would already have invented it. However, this objection can be overcome if one assumes a stable and repetitive universe in which rational actors make efficient use of the information available to them. In this environment, uncertainty disappears to be replaced by calculable risk. Shocks and mistakes may occur but these will cancel each other out, so that, on average, people get what they expect.
An important implication of this view is that shares are always correctly priced. This is the basis of the so-called efficient market hypothesis that has dominated financial economics. It led bankers into blind faith in their mathematical forecasting models. It led governments and regulators to discount the possibility that financial markets could implode. It led to what Alan Greenspan called (after he had stepped down as chairman of the US Federal Reserve) "the underpricing of risk worldwide".