quarta-feira, 8 de setembro de 2010

Artigo do FT que questiona a visão dos economistas e a validade científica dos seus modelos

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Artigo enviado pelo meu amigo Carlos Lessa Brandão.
A frase em vermelho abaixo quase resvalou na crítica destrutiva de Nicholas Georgescu-Roegen, pela qual os economistas tradicionais assumem perfeita previsibilidade, reversibilidade, substitutability e neutralidade do sistema econômico e seus efeitos sistêmicos, principalmente em relação à Natureza. Com esse sistema de idéias, que não é falho só apenas do ponto de vista econômico, mas também do ponto de vista sistêmico, a rota suicida segue inalterada com uma geração espontânea de mitos, como por exemplo, economia do baixo carbono, energia limpa e outras tecnologias mirabolantes que ilusoriamente arrumam a casa sem ser necessário nenhuma mudança de paradigma (ou de ganância e interesses).
A melhor forma de analisar o cenário sempre foi através de fatos históricos estilizados de repetições de fenômenos, ao invés de previsores por meio de modelos econométricos questionáveis terrivelmente falhos. Os melhores economistas são os que encontram esse padrão na história dos fenômenos econômicos ao longo do tempo, mas por não versarem nessa matematiqueira sem sentido, são vistos com preconceito, embora suas análises são muito melhores.
Excertos da matéria abaixo:
... buildings constructed according to the laws of physics seem to stand, whereas policies and trading systems constructed according to the “laws” of economics have a nasty habit of collapsing.
The vanity of economists needs to be challenged. Above all, their claim to scientific rigour – buttressed by models and equations – must be treated much more sceptically.
If science is defined by its ability to forecast the future, the failure of much of the economics profession to see the crisis coming should be a cause of great concern.
With the exception of a few deluded Marxists, historians know that their work cannot be used to predict the future. History can suggest lessons and parallels and provide wisdom – but what it cannot do is provide a sociological equivalent of the laws of physics. Yet this seems to be the aspiration of many economists, who notoriously suffer from “physics envy.
Rather than seeking to ape physicists, however, perhaps it is time for economists to learn a few lessons from history, or more precisely from historians.
http://www.ft.com/cms/s/0/93d9ff2a-b9e1-11df-8804-00144feabdc0.html?ftcamp=rss&ftcamp=crm/email/201097/nbe/Comment/product

Sweep economists off their throne
By Gideon Rachman
Published: September 6 2010 20:08 | Last updated: September 6 2010 20:08

When Paul Krugman, a Nobel prize-winning economist, clashed with Niall Ferguson, a famous historian (and FT contributing editor), over how best to respond to the economic crisis, Prof Ferguson’s response was humorously humble. “A cat may look at a king,” he wrote, “and sometimes a historian can challenge an economist.”
As the proud owner of a huge grey Chartreux cat, and a history graduate, I believe that it is time to overturn this implicit intellectual hierarchy. The cats must unsheath their claws and lacerate the kings, ripping away their regal pretensions. The vanity of economists needs to be challenged. Above all, their claim to scientific rigour – buttressed by models and equations – must be treated much more sceptically.
When things were going well for the global economy, the prestige of economists rose steadily. They were the gurus of the age of globalisation. Governments, consultancies and investment banks rushed to hire economists, who were thought to possess vital skills and information. Historians, by contrast, were treated as mere entertainers and storytellers. They were archive-grubbers, lacking in scientific method – good on television, but useless with a PowerPoint and no help in government or the boardroom.
There has been some self-examination and soul-searching within the economics profession since the onset of the financial crisis. Joseph Stiglitz, another Nobel prize-winning economist, has suggested that: “If science is defined by its ability to forecast the future, the failure of much of the economics profession to see the crisis coming should be a cause of great concern.” Yet Prof Stiglitz’s conclusion is disappointingly mild: economists must simply search for new “paradigms” – and then presumably go back into the business of scientific prediction.
For somebody educated as a historian, there is an obvious alternative conclusion to draw from Prof Stiglitz’s opening observation. And that is to conclude that the entire attempt to treat economics as a “science ... defined by its ability to forecast the future” is misconceived.
The current debate reminds me of an after-dinner speech I once heard given in the mid-1980s by the late Geoffrey Elton, who was then regius professor of modern history at Cambridge. Elton argued that the function of the historian was to concentrate on the particular and the specific and to puncture the pretensions of social scientists, with their constant and futile effort to derive general, predictive laws from the study of the past. At the time – and through a fug of cigar smoke and alcohol fumes – it struck me as a curiously conservative and negative definition of the role of the historian. Our task, it seemed, was simply to stick our hand up and say: “Actually, chaps, it was a bit more complicated than that.”
But, in the current intellectual climate, it seems to me that Elton was saying something important. He was defending the empirical method and setting boundaries for what can be expected from the study of the past. With the exception of a few deluded Marxists, historians know that their work cannot be used to predict the future. History can suggest lessons and parallels and provide wisdom – but what it cannot do is provide a sociological equivalent of the laws of physics. Yet this seems to be the aspiration of many economists, who notoriously suffer from “physics envy”.
Some might respond that such a critique exaggerates the hardness of “hard” science and the softness of economics. Maybe so: but then again buildings constructed according to the laws of physics seem to stand, whereas policies and trading systems constructed according to the “laws” of economics have a nasty habit of collapsing.
Yet economists seem unlikely to abandon the belief that theirs is a discipline that makes “progress” and settles issues, in a way that resembles a hard science such as physics or chemistry. Ben Bernanke, the current head of the Federal Reserve, exemplified this belief in a famous speech in 2004 on the “Great Moderation”, in which he argued that there had been a “substantial decline in macroeconomic volatility”, largely because of improved monetary policy, based on advances in economic thinking.
The subsequent financial and economic crash may have dented the confidence of some economists in particular tenets of their discipline. But the Great Recession seems unlikely to dissuade many economists from the more fundamental belief that there are, indeed, predictive “laws” out there, just waiting to be discovered.
Rather than seeking to ape physicists, however, perhaps it is time for economists to learn a few lessons from history, or more precisely from historians.
The serious study of history goes all the way back to Herodotus in the fifth century BC. And yet today’s historians are far humbler about what they can hope to achieve than modern economists. Historians know that no big question is ever definitively settled. They know that every big and interesting topic will be revisited, revised and examined from new angles. Each generation will reinterpret the past and deliver its own verdict.
This way of looking at the world is less obviously useful to practical men, seeking to make decisions. But maybe it is time for an alternative to the brash certainties, peddled by those pseudo-scientists, otherwise known as economists.
gideon.rachman@ft.com
Copyright The Financial Times Limited 2010.

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