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By Philippe Legrain 4 COMMENTS

In this week’s FT, Gideon Rachman argued that “maybe it is time for an alternative to the brash certainties, peddled by those pseudo-scientists, otherwise known as economists.”

Tim Harford then hit back with a defence of economics, and Diane Coyle has also joined the fray.

I know, like and respect all three of them, and I think they all make valid points. As someone who studied economics and writes about it, yet has always found some of the central tenets of mainstream macroeconomics unconvincing, I think to a certain extent they are talking at cross purposes.

Gideon’s main critique is of macroeconomics, while Tim’s robust defence is primarily of microeconomics. Gideon points out that economics isn’t physics, and Tim replies that it is more than history. A dispassionate observer might conclude that they both have a point.

Focusing on mainstream macroeconomics, though, I agree with Gideon that a lot of it is bunk.

Neoclassical economics assumes that markets move from one defined equilibrium to another, and assumes away the influence of financial markets altogether. Hence the inability to predict, or even expect, the financial crisis.

Many free-marketeers are attracted to neoclassical economics because they think it “proves” that markets are efficient and that government intervention generally makes matters worse.

In fact, it does no such thing, because if you assume away uncertainty, an all-knowing central planner could allocate resources just as efficiently as free markets.

New Keynesian economics, which grafts a rationale for government intervention on to neoclassical economics, is equally misguided.

It suffers from most of the same flaws that neoclassical economics does. And it isn’t Keynesian at all, since it basically ignores the crucial role of uncertainty.

I think our understanding of macroeconomics should draw on a synthesis of Hayek and Keynes.

While they differed on many things, they both understood that economies are continually in flux, that the future is fundamentally unknowable (not a point on a known probability distribution),and hence that the role of finance and entrepreneurs – both of whom create markets in the future – is crucial.

As I wrote in the conclusion to my new book, Aftershock:

Market economies are not computable machines that shift predictably from one steady state to another, they are dynamic, unfathomably complex organisms that are forever evolving – unsurprisingly, since they are made up of millions of human beings continually interacting with each other. Nor is economic growth a mechanical process oiled by new technologies that appear metronomically as manna from heaven. It is an ongoing voyage of discovery into an unknowable future, fuelled by ingenuity and energy, trialled by enterprising businesses and stimulated by competition within a framework of supportive institutions.

Posted 12 Sep 2010 in Blog
  1. koenfucius says:

    It seems to me that while apparently criticizing Economics as a science, Rachman is actually criticizing the practitioners of Economics – or at least some of them.

    Much of his beef seems to relate to certain economists’ pretence that they can predict the future. It is indeed tempting, when you have a fancy model that has a pretty good fit with a narrow subset of the recent past, to believe that the near (or even far future) will also conform to your model.

    Perhaps even the cleverest of economists are not immune to a dose of confirmation bias – like most of the rest of us, I guess they too probably tend to rather favour the evidence supporting their beliefs than the evidence that challenges them. If reality doesn’t conform to the model, then reality must be wrong…

    I think that, ultimately, both macroeconomics and microeconomics are subject to the vagaries of human behaviour. Models are therefore at best, to use a favourite quote of John Kay, “illuminating but not true”.

    Behavioural economists for sure have their work cut out!

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