John Kay - Economics may be dismal, but it is not a science

Economics may be dismal, but it is not a science

The macroeconomics taught in advanced economics today is largely based on analysis labelled dynamic stochastic general equilibrium. The unappealing title gives the game away: the theorists are mostly talking to themselves. Their theories proved virtually useless in anticipating the crisis, analysing its development and recommending measures to deal with it.

A remarkably distinguished group of economists gathered last weekend for the inaugural conference of the Institute for New Economic Thinking, an initiative of George Soros. They were soul searching over the failures of economics in the recent crisis. Such failures are most evident in two areas: the inadequacies of the efficient market hypothesis, the bedrock of modern financial economics, and the irrelevance of recent macroeconomic theory.

The central idea of the efficient market hypothesis is that prices represent the best estimate of the underlying value of assets. This thesis has recently taken a battering. The boom and bust in the money markets was precipitated by a US housing bubble. That bubble followed the New Economy fiasco and was preceded by the near-failure of Long Term Capital Management, a hedge fund designed to showcase sophisticated financial economics.

The macroeconomics taught in advanced economics today is largely based on analysis labelled dynamic stochastic general equilibrium. The unappealing title gives the game away: the theorists are mostly talking to themselves. Their theories proved virtually useless in anticipating the crisis, analysing its development and recommending measures to deal with it.

Recent economic policy debates have not only largely ignored DSGE, but have also been remarkably similar to the economic policy debates of the 1930s, although they have been resolved differently. The economists quoted most often are John Maynard Keynes and Hyman Minsky, both of whom are dead.

Both the efficient market hypothesis and DSGE are associated with the idea of rational expectations – which might be described as the idea that households and companies make economic decisions as if they had available to them all the information about the world that might be available. If you wonder why such an implausible notion has won wide acceptance, part of the explanation lies in its conservative implications. Under rational expectations, not only do firms and households know already as much as policymakers, but they also anticipate what the government itself will do, so the best thing government can do is to remain predictable. Most economic policy is futile.

So is most interference in free markets. There is no room for the notion that people bought subprime mortgages or securitised products based on them because they knew less than the people who sold them. When the men and women of Goldman Sachs perform “God’s work”, the profits they make come not from information advantages, but from the value of their services. The economic role of government is to keep markets working.

These theories have appeal beyond the ranks of the rich and conservative for a deeper reason. If there were a simple, single, universal theory of economic behaviour, then the suite of arguments comprising rational expectations, efficient markets and DSEG would be that theory. Any other way of describing the world would have to recognise that what people do depends on their fallible beliefs and perceptions, would have to acknowledge uncertainty, and would accommodate the dependence of actions on changing social and cultural norms. Models could not then be universal: they would have to be specific to contexts.

The standard approach has the appearance of science in its ability to generate clear predictions from a small number of axioms. But only the appearance, since these predictions are mostly false. The environment actually faced by investors and economic policymakers is one in which actions do depend on beliefs and perceptions, must deal with uncertainty and are the product of a social context. There is no universal economic theory, and new economic thinking must necessarily be eclectic. That insight is Keynes’s greatest legacy.

 

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