Heh, še en brilijanten komentar Noaha Smitha, ki pojasnjuje, kako je sedanja finančna kriza makroekonomijo popeljala nekoliko stran od elegantne matematične teorije in tja kamor spada: k analizi podatkov. Pri čemer teorija služi zgolj za pojasnitev dogajanja v realnem gospodarstvu, ne pa izmišljevanju tega, kaj naj bi se v realnem gospodarstvu dogajalo, da bi bilo v skladu z matematizirano teorijo, ki temelji na ideoloških premisah free-market ekonomije.

Če niste “iz foha”, torej iz akademske makroekonomije, se vam bo prejšnji stavek zdel absolutno bedast. In pri tem imate popolnoma prav. Toda na žalost je makroekonomija po začetku 1970. let z “mikrofundirano revolucijo” iz Lucasovega brloga v Chicagu zašla v polje elegantne teorije in povozila empirijo. Ena izmed posledic tega je, da naj bi bili monetarna in fiskalna politika popolnoma nepotrebni. Spet druga izmed posledic tega razvoja pa je, da smo dobili elegantne velike makroekonomske modele (DSGE modeli) z optimizacijskim obnašanjem reprezentativnih agentov, ki optimizirajo v prihodnost, ki pa so se v praksi izkazali kot popolnoma neuporabna igračka za velike fante.

This joke is so commonly applied to economists that no one even knows who said it originally. The idea fits with the stereotype of economists as out-of-touch theory-obsessed philosophers, wasting time arguing about what would happen in a made-up world of their own devising, while all around them the real world unfolds in ways that are totally different. 

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Now, in macroeconomics — the study of business cycles and long-term growth — this shift has been a lot harder and slower. The reason is that in macro, there’s just much less data. History only happens once, and it’s hard to know to what degree the future will be like the past. To make matters worse, there’s just not that much data out there — we’ve been keeping good records for less than a century. 

So where there’s less data, we would expect theory to expand to fill the gap. And in fact, macro is the main battleground for a perpetual argument about whether theory or evidence should be in the driver’s seat. Ed Prescott, a Nobel-winning economist, famously declared in 1986 that theory was “ahead” of measurement in business cycle theory. But since the financial crisis, there has been a clamor to elevate data to its rightful place.

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For example, consider the work of rising stars Emi Nakamura and Jon Steinsson of Columbia University. The dynamic duo of Nakamura and Steinsson set out to investigate the idea that price “stickiness” — the inability of prices to adjust to changing economic conditions — is a big factor in causing recessions. The stickier prices are, the more a fall in aggregate demand will damage the economy. Nakamura and Steinsson found that a lot of the non-sticky prices in the economy are concentrated in a few items, such as gasoline, or the result of temporary sales and discounts. 

When you account for these price patterns, overall prices in the economy look a lot stickier than economists previously thought. That means that aggregate demand — the same force that Paul Krugman constantly talks about in his blog — is a more important factor than economists had previously thought. It also implies that policies such as monetary easing and fiscal stimulus will be effective in counteracting the effect of the sticky prices and bringing the economy back from recession. Other teams of economists, using different methodologies, have recently found very similar patterns. Opponents of monetary easing and fiscal stimulus are going to have to confront these facts. 

Vir: Noah Smith, BloombergView