Zakaj samo v makroekonomiji razvoj teorije zavira razvoj?

Bloomberg se je v zadnjih letih razvil v najbolj progresivni poslovni medij, ki prekaša tudi The Economista. Ne samo njegovi novinarji in kolumnisti prebijajo (konzervativne) meje v poročanju o ekonomskih zadevah, tokrat so svoje dodali še uredniki, ki so kolektivno objavili uredniški komentar o akademski makroekonomiji, ki je skrenila s poti. Natančneje, zadnja 4 desetletja se premika vzvratno. V smeri matematične elegance, temelječe na divjih in povsem izvenzemeljskih predpostavkah, ter stran od dejanske uporabnosti v realnem življenju. Izmed vseh znanstvenih ved samo v makroekonomiji razvoj teorije zavira razvoj.

Uredniki Bloomberga zapišejo še, da še sreča, da ob izbruhu finančne krize v 2008 Kongres in Obamova administracija nista sledili naukom “sodobne” makroekonomije, ki (po “zaslugi” neumnih predpostavk) predvidevata, da ne monetarni in ne fiskalni stimulus nimata nobenih realnih učinkov, pač pa so raje sledili “zastarelemu” keynesianizmu.

No, kljub temu pa nič ne kaže, da bi se akademska makroekonomija nad tem resno zamislila in spremenila kurz. Nasprotno.

The trouble is, too many theorists — especially in the mainstream of the discipline — have drifted far from the real world. Their ambition has been to build mathematically elegant and internally consistent models of the economy, even if that requires wholly unrealistic assumptions. Granted, just as maps have to simplify complex terrain, theoretical models must ignore aspects of reality to be any use. But there’s a line between simplification and gross distortion, and modern macroeconomics has crossed it.

Before the 2008 financial crisis, for example, the standard models more or less ignored finance. No banks, no indebtedness, no leverage. As a result, they couldn’t make sense of the worst global recession since the 1930s. They also typically asserted that fiscal stimulus had little or no effect on consumer spending, which follows from the model’s mathematically convenient assumptions. If President Barack Obama and Congress had applied such thinking in 2009, the recession would have been much worse. Fortunately, policy was guided not by modern macro but by old-fashioned Keynesianism, long since abandoned by the academy.

Given such spectacular failures, you’d think the profession would have gone back to the drawing board. It hasn’t. True, some tweaks have been attempted, and some scholars have done valuable work on the history of crises, the role of household debt, the drivers of inequality, and much else. But the error at the core of modern macroeconomics — that mathematical consistency matters more than empirical relevance — prevails. Just glance through the leading academic journals. Or maybe take our word for it.

Reviving economics as a science will require economists to act more like scientists. If models are refuted by the observable world, toss them out. Rely on experiments, data and replication to test theories and understand how people and companies really behave. Editors of the most prestigious (career-advancing) journals should open their pages to research that challenges the standard theories, even if it doesn’t yet point to encompassing new alternatives.

Practitioners can help by being more discerning. Whenever an economist says “in our model,” beware. Demand to know what assumptions the model makes, and question those assumptions as severely as the theorists test for valid inference — because valid inference from bogus assumptions is useless. Where possible, and in the same spirit, pay closest attention to empirical and historical research.

In just about every branch of science, theoretical research has been crucial to achieving breakthroughs. In macroeconomics, it has held progress back. To stop the discipline fading into irrelevance, this will have to change. Who knows? If it does, economists might finally start getting some respect.

Vir: Bloomberg

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