Zakaj se je “freshwater ideologija” tako hitro razširila

Paul Romer in Paul Krugman nadaljujeta diskusijo, zakaj se je “freshwater ideologija” (torej ideologija ekonomistov okrog Chicago university (predvsem Roberta Lucasa), da so posamezniki racionalni, da se trgi samourejajo in da korekcije z monetarno in fiskalno politiko niso potrebne) tako hitro razširila. Romer pravi, da je del odgovora v tem, da je Lucasovo predpostavko racionalnih pričakovanj pričakal zelo sarkastičen sprejem s strani nobelovca Roberta Solowa (M.I.T.). Zato naj  bi se freshwater ekonomisti zaprli v svoj matematični kokon, v katerem naj bi njihova teorija delovala (no, Paul Romer pravi, da tudi v čisti matematiki ta teorija ne velja, in da so predpostavke močno nategnjene, le da se zelo redki posamezniki odločijo prebiti se skozi to matematiko in to odkriti).

Vendar pa je Romer zelo zelo prijazen, zaradi česar je pri zgornji prizanesljivosti malce zgrešil. Kajti, kot pravi že sam, je ne glede na sarkastičen sprejem uveljavljenih ekonomistov freshwater ideologija bliskovito prevzela vse doktorske ekonomske šole, na čelu z M.I.T. S tem se strinja tudi Paul Krugman, ki pravi, da sta razloga drugje. Prvi je v politični zmagi konzervativcev, ki ji je ta freshwater ideologija – roke stran od gospodarstva – zelo ustrezala. Drugi pa je v metodološkem orodju – potrebno je bilo investirati v matematiko, da bi razumeli, kaj Lucas & co. sploh počnejo. Tisti redki, ki so to naredili, imajo interes, da vztrajajo, da je to edini način, kako se dela teoretična ekonomija.

No, Paul Romer, ki je bil eden izmed njih, zdaj dokazuje, kako grdo so nategnili matematiko in da uporabljene predpostavke bodisi matematično bodisi vsebinsko preprosto ne veljajo. Romerjev križarski pohod, imenovan “mathiness” (matematičnost), proti zlorabi matematike v ideološke namene, je zato tako zelo osvežilna zadeva, saj Lucasovo freshwater ideologijo, preoblečeno v matematične formule, razsuva od znotraj.

But Romer’s account of the great wrong turn still sounds much too contingent to me, and not just because, as he himself says, rational expectations quickly took over much modeling at MIT.

At least as I perceived it then — and remember, I was a grad student as much of this was going on — there were two other big factors.

First, there was a political component. Equilibrium business cycle theory denied that fiscal or monetary policy could play a useful role in managing the economy, and this was a very appealing conclusion on one side of the political spectrum. This surely was a big reason the freshwater school immediately declared total victory over Keynes well before its approach had been properly vetted, and why it could not back down when the vetting actually took place and the doctrine was found wanting.

Second — and this may be less apparent to non-economists — there was the toolkit factor. Lucas-type models introduced a new set of modeling and mathematical tools — tools that required a significant investment of time and effort to learn, but which, once learned, let you impress everyone with your technical proficiency. For those who had made that investment, there was a real incentive to insist that models using those tools, and only models using those tools, were the way to go in all future research.

And of course at this point all of these factors have been greatly reinforced by the law of diminishing disciples: Lucas’s intellectual grandchildren are utterly unable to consider the possibility that they might be on the wrong track.

Vir: Paul Krugman

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