Sunday, May 03, 2009

Ainda a teoria austriaca do ciclo económico (III)

I’ve long promised a post on Austrian Business Cycle Theory, and here it is. For those who would rather get straight to the conclusion, it’s one I share in broad terms with most of the mainstream economists who’ve looked at the theory, from Tyler Cowen, Bryan Caplan and Gordon Tullock at the libertarian/Chicago end of the spectrum to Keynesians like Paul Krugman and Brad DeLong.

To sum up, although the Austrian School was at the forefront of business cycle theory in the 1920s, it hasn’t developed in any positive way since then. The central idea of the credit cycle is an important one, particularly as it applies to the business cycle in the presence of a largely unregulated financial system. But the Austrians balked at the interventionist implications of their own position, and failed to engage seriously with Keynesian ideas.

The result (like orthodox Marxism) is a research program that was active and progressive a century or so ago but has now become an ossified dogma. Like all such dogmatic orthodoxies, it provides believers with the illusion of a complete explanation but cease to respond in a progressive way to empirical violations of its predictions or to theoretical objections. To the extent that anything positive remains, it is likely to be developed by non-Austrians such as the post-Keynesian followers of Hyman Minsky.


According to the theory, the business cycle unfolds in the following way. The money supply expands either because of an inflow of gold, printing of fiat money or financial innovations that increase the ratio of the effective money supply to the monetary base. The result is lower interest rates. Low interest rates tend to stimulate borrowing from the banking system. This in turn leads to an unsustainable boom during which the artificially stimulated borrowing seeks out diminishing investment opportunities. This boom results in widespread malinvestments, causing capital resources to be misallocated into areas that would not attract investment if price signals were not distorted. A correction or credit crunch occurs when credit creation cannot be sustained. Markets finally clear, causing resources to be reallocated back towards more efficient uses.

At the time it was put forward, the Mises-Hayek business cycle theory was actually a pretty big theoretical advance. The main competitors were the orthodox defenders of Says Law, who denied that a business cycle was possible (unemployment being attributed to unions or government-imposed minumum wages), and the Marxists who offered a model of catastrophic crisis driven by the declining rate of profit.

Both Marxism and classical economics were characterized by the assumption that money is neutral, a ‘veil’ over real transactions. On the classical theory, if the quantity of money suddenly doubled, with no change in the real productive capacity of the economy, prices and wages would rise rapidly. Once the price level had doubled the previous equilibrium would be restored. Says Law (every offer to supply a good service implies a demand to buy some other good or service) which is obviously true in a barter economy, was assumed to hold also for a money economy, and therefore to ensure that equilibrium involved full employment

The Austrians were the first to offer a good reason for the non-neutrality of money. Expansion of the money supply will lower (short-term) interest rates and therefore make investments more attractive.

There’s an obvious implication about the (sub)optimality of market outcomes here, though more obvious to a generation of economists for whom arguments about rational expectations are second nature than it was 100 years ago. If investors correctly anticipate that a decline in interest rates will be temporary, they won’t evaluate long-term investments on the basis of current rates. So, the Austrian story requires either a failure of rational expectations, or a capital market failure that means that individuals rationally choose to make ‘bad’ investments on the assumption that someone else will bear the cost. And if either of these conditions apply, there’s no reason to think that market outcomes will be optimal in general.

A closely related point is that, unless Say’s Law is violated, the Austrian model implies that consumption should be negatively correlated with investment over the business cycle, whereas in fact the opposite is true. To the extent that booms are driven by mistaken beliefs that investments have become more profitable, they are typically characterized by high, not low, consumption.

Finally, the Austrian theory didn’t say much about labour markets, but for most people, unemployment is what makes the business cycle such a problem. It was left to Keynes to produce a theory of how the non-neutrality of money could produce sustained unemployment.

The credit cycle idea can easily be combined with a Keynesian account of under-employment equilibrium, and even more easily with the Keynesian idea of ‘animal spirits’. This was done most prominently by Minsky, and the animsal spirits idea has recently revived by Akerlof and Shiller. I suspect that the macroeconomic model that emerges from the current crisis will have a recognisably Austrian flavour..

Unfortunately, having put taken the first steps in the direction of a serious theory of the business cycle, Hayek and Mises spent the rest of their lives running hard in the opposite direction. As Laidler observes, they took a nihilistic ‘liquidationist’ view in the Great Depression, a position that is not entailed by the theory, but reflects an a priori commitment to laissez-faire. The result was that Hayek lost support even from initial sympathisers like Dennis Robertson. And this mistake has hardened into dogma in the hands of their successors.

The modern Austrian school has tried to argue that the business cycle they describe is caused in some way by government policy, though the choice of policy varies from Austrian to Austrian - some blame paper money and want a gold standard, others blame central banks, some want a strict prohibition on fractional reserve banking while others favour a laissez-faire policy of free banking, where anyone who wants can print money and others still (Hayek for example) a system of competing currencies.


To sum up, the version of the Austrian Business Cycle Theory originally developed by Hayek and Mises gives strong reasons to think that an unregulated financial system will be prone to booms and busts and that this will be true for a wide range of monetary systems, particularly including gold standard systems. But that is only part of what is needed for a complete account of the business cycle, and the theory can only be made coherent with a broadly Keynesian model of equilibrium unemployment. Trying to tie Austrian Business Cycle Theory to Austrian prejudices against government intervention has been a recipe for intellectual and policy disaster and theoretical stagnation.

Alguns pontos:

- A critica (que não transcrevi) que o autor faz a Rothbard não me parece muito correcta (creio que Rothbard responsabilizava pelos ciclos, não apenas os bancos centrais, como as reservas fracionária)

- Eu tenho uma teoria (muito particular...) de que é possivel defender o keynesianismo sem defender a intervenção estatal (Keynes morria outra vez se ouvisse alguém dizer isso). Ei-de explicá-la algum dia (uma pista: tem a ver com a concorrência entre moedas à la Hayek, misturada com um bocadinho de Proudhon). O que deduzo daí é que, mesmo com os seus preconceitos anti-estatistas, os "austríacos" poderiam ter aceite o keynesianismo (isto é, o tipo muito peculiar de keynesianismo que eu vou apresentar um dia destes).

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