segunda-feira, 10 de outubro de 2011

Nobel de economia 2011

Os suecos realmente tem um grande senso de humor e coragem, afinal em que pese a referência aos trabalhos empiricos do Thomas Sargent, resta o fato dele ter sido um dos lideres da revolucionária - ou contra-revolucionária para alguns - escola das expectativas racionais/novos classicos. Sua contribuição teorica a macroeconomia é inegavel, alem de ser autor de um paper classico sobre o fim de quatro hiperinflação Premio mais que merecido. O mesmo, alias, se aplica ao Sims, fundamental na formulação dos instrumentos necessários aos trabalho empiricos em macroeconomia. É uma escolha que desagrada aqueles mais interessados em questões ideológicas que teóricas, mas não os que sem concordar com a abordagem do Sargent,reconhecem sua grande contribuição a teoria econômica.


Two economists known for their work on integrating expectations more sensibly into models of the economy have won the 2011 economics prize in memory of Alfred Nobel, in a bold decision which will be seen as honouring academics whose work many blame as partly responsible for the financial crisis.

The Royal Swedish Academy of Sciences awarded the Nobel prize to professors Thomas Sargent, of New York University, and Christopher Sims, of Princeton University, for their independent “empirical research on cause and effect in the macroeconomy”, mostly in the 1970s and 1980s.


The citation was specific in honouring the “empirical” or practical rather than theoretical work of both economists, since Prof Sargent is best known for his work on rational expectations theory, which underpinned the belief that financial markets work efficiently.

Prof Sargent has long said rational expectations should not be seen as a school of thought or an ideological statement, but a way of modelling how people think and react to policy changes or events. The concept, he wrote, came to the same conclusion as Abraham Lincoln: “You can fool some of the people all of the time, and all of the people some of the time, but you cannot fool all of the people all of the time”.

Prof Sims was awarded his share of the prize for his statistical models underpinning many macro-economic models today. His work started with “vector autoregression” – statistical models which had better predictive power than many traditional models used in the 1970s. He augmented these models further by making them work in a dynamic setting with rational responses to shocks such as changes in interest rates.

Professor Marvin Goodfriend of Carnegie Mellon university said on Monday that the two winners took research on expectations to a new level. “It was Robert Lucas who persuaded the profession that expectations mattered, but it was Sargent and Sims who pioneered the empirical work on how to model expectations in a statistical and practical way”.

Sargent’s work on expectations and monetary policy has fresh relevance for western economies thrown into uncharted territory. Much of his research has focused on how inflationary episodes end. In his book The Conquest of American Inflation, he studied the rise in inflation in the 1960s and 1970s and the subsequent “great moderation”.

He argued that these changes reflected the way individuals in the economy gradually updated their expectations about what economic policymakers were trying to do, rather than by shifts in the policy itself. As Sargent himself observed, today’s economic developments such as the eurozone crisis are driven strongly by expectations.

Perhaps the main application of rational expectations theory is the efficient market hypothesis, which asserts that the price of an asset contains all relevant information and cannot systematically be over-or under valued. It was the widespread belief in this theory that led to the view that the credit bubble before the financial crisis did not exist.

Prof Sargent rose to prominence in the 1970s by showing that if rational expectations were added to many standard economic models of the time, predictions of government effectiveness in controlling the economy would disappear. He did not, however, believe that governments were in fact powerless.

“We try to experiment in our models before we wreck the world. So that we don’t wreck the world, right?” he said in an interview with the prize-giving committee on Monday.

In this he received support from Prof Goodfriend. “The methodology of rational expectations will outlive any current model of the economy. It’s more fundamental in a way. It’s a fundamental, sensible idea, he said.

Fonte: FT