O dezbatere care nu ne interesează

În bătălia ideologică din ultimii ani celor care spun că nu marxismul, sau comunismul, sunt vinovate de ceea ce s-a întâmplat în totalitarismele estice din Europa, ci marxiştii şi comuniştii care au citit şi aplicat greşit modelele, li s-a refuzat net acest argument, în fond de bun simţ. Acum argumentul revine, dar în apărarea unor modele economice, cum este EMH(efficient-markets hypothesis), criticat violent de mulţi şi considerat a fi un vinovat de actuala criză.

"The EMH, to be sure, has loyal defenders. “There are models, and there are those who use the models,” says Myron Scholes, who in 1997 won the Nobel prize in economics for his part in creating the most widely used model in the finance industry—the Black-Scholes formula for pricing options. Mr Scholes thinks much of the blame for the recent woe should be pinned not on economists’ theories and models but on those on Wall Street and in the City who pushed them too far in practice."

The Economist, din care am citat, dedică în numărul de azi un spaţiu generos analizei stării teoriilor şi modelelor economice, ştiinţei economice, în general, din perspectiva crizei economice. De fapt, mulţi văd această criză ca pe un eşec al economiştilor, nu doar al pieţelor şi al decidenţilor din domeniu.

Scurt şi brutal spus, "The past 30 years of macroeconomics training at American and British universities were a “costly waste of time". Nici mai mult, nici mai puţin! "The macroeconomic crisis of the past two years is also provoking a crisis of confidence in macroeconomics. In the last of his Lionel Robbins lectures at the LSE on June 10th, Mr Krugman feared that most macroeconomics of the past 30 years was “spectacularly useless at best, and positively harmful at worst. These internal critics argue that economists missed the origins of the crisis; failed to appreciate its worst symptoms; and cannot now agree about the cure. In other words, economists misread the economy on the way up, misread it on the way down and now mistake the right way out.” Sună al dracului de încurajator!

Cum s-a ajuns aici, din punct de vedere al teoriilor economice? "For about a decade before the crisis, macroeconomists once again appeared to know what they were doing. Their thinking was embodied in a new genre of working models of the economy, called “dynamic stochastic general equilibrium” (DSGE) models. These helped guide deliberations at several central banks. Mr Buiter, who helped set interest rates at the Bank of England from 1997 to 2000, believes the latest academic theories had a profound influence there. He now thinks this influence was baleful. On his blog, Mr Buiter argues that a training in modern macroeconomics was a “severe handicap” at the onset of the financial crisis, when the central bank had to “switch gears” from preserving price stability to safeguarding financial stability. Modern macroeconomists worried about the prices of goods and services, but neglected the prices of assets. This was partly because they had too much faith in financial markets. If asset prices reflect economic fundamentals, why not just model the fundamentals, ignoring the shadow they cast on Wall Street? It was also because they had too little interest in the inner workings of the financial system. “Philosophically speaking,” writes Perry Mehrling of Barnard College, Columbia University, economists are “materialists” for whom “bags of wheat are more important than stacks of bonds.” Finance is a veil, obscuring what really matters. As a poet once said, “promises of payment/Are neither food nor raiment”. In many macroeconomic models, therefore, insolvencies cannot occur. Financial intermediaries, like banks, often don’t exist. And whether firms finance themselves with equity or debt is a matter of indifference. The Bank of England’s DSGE model, for example, does not even try to incorporate financial middlemen, such as banks. “The model is not, therefore, directly useful for issues where financial intermediation is of first-order importance,” its designers admit. The present crisis is, unfortunately, one of those issues."

Mai pe scurt, una dintre legile lui Murphy a fost de bază: dacă datele experimentale contrazic modelul teoretic, ignoră-le! Sigur că absenţa unor elemente din modelele teoretice nu a fost întâmplătoare, ci deliberată. Modelul era doar pentru proşti, pentru a le demonstra că nu există riscuri dacă investesc în tot felul de "produse exotice", care erau din start proiectate toxice.

Discuţia se poartă în jurul modelelor economice, în special despre limitele şi slăbiciunile lor. Întrebarea este dacă se continuă cu ele, după reglajele de rigoare, sau se imaginează ceva nou: " These basic models are also influential because of their simplicity. Faced with the “blooming, buzzing confusion” of the real world, policymakers often fall back on the highest-order principles and the broadest presumptions. More specific, nuanced theories are often less versatile. They shed light on whatever they were designed to explain, but little beyond. Would economists be better off starting from somewhere else? Some think so. They draw inspiration from neglected prophets, like Minsky, who recognised that the “real” economy was inseparable from the financial. Such prophets were neglected not for what they said, but for the way they said it. Today’s economists tend to be open-minded about content, but doctrinaire about form. They are more wedded to their techniques than to their theories. They will believe something when they can model it.

Mr Colander, therefore, thinks economics requires a revolution in technique. Instead of solving models “by hand”, using economists’ powers of deduction, he proposes simulating economies on the computer. In this line of research, the economist specifies simple rules of thumb by which agents interact with each other, and then lets the computer go to work, grinding out repeated simulations to reveal what kind of unforeseen patterns might emerge. If he is right, then macroeconomists, like zombie banks, must write off many of their past intellectual investments before they can make progress again.

Mr Krugman, by contrast, thinks reform is more likely to come from within. Keynes, he observes, was a “consummate insider”, who understood the theory he was demolishing precisely because he was once convinced by it. In the meantime, he says, macroeconomists should turn to patient empirical spadework, documenting crises past and present, in the hope that a fresh theory might later make sense of it all. "

Până una-alta, noi suntem lipsiţi de grija asta. Economie de modelizat nu mai avem, economiştii noştri sunt cu capra la raze, politicienii, la fel, iar singurul lucru care ne interesează este cine cu cine şi-o pune!