The great moderation is over & so is the overconfidence in monetary policy

sagt Mark Thoma. Nachdem Robert Lucas 2003 behauptete dass das "central problem of
depression-prevention has been solved for all practical purposes" und sich die Vorstellung der großen Dämpfung des Konjunktur über die letzten 30 Jahre sich als falsch herausstellt, sollten die Ökonomen der Fiskalpolitik wieder eine wichtigere Rolle zuweisen:

If legislators understand and believe that early and decisive fiscal policy action is a crucial part of the policy mix needed to avoid large down turns, and especially if their constituents begin to understand this, perhaps timeliness of fiscal policy will be less will be less of an issue. Legislators have certainly shown that they can implement some types of policies - tax rebates - very quickly when they are sufficiently motivated to do so, and when they have the president's support.

Economists have a role to play here. We have put monetary policy on too high of a pedestal, and we have unfairly shunted fiscal policy into secondary status when it deserves a more prominent role. If I have a complaint about Depression Economics, it's that it does not do enough to offset this perception. Economists need to help restore confidence in fiscal policy, and they need to be more realistic about monetary policy. The updated version of Depression Economics takes a step in this direction, the last chapter in particular, but much, much more is needed. I trust, however, that Paul Krugman will continue to use his powerful public forum to help both policymakers and the public understand the essential role that fiscal policy plays in avoiding severe economic downturns.

Die Keynes'sche Einsicht, dass in der Depression andere Regeln gelten im moderneren Krugman cover:

Right now the world economy is in a nosedive, and understanding what I call "depression economics" -- the weird world you get into when even a zero interest rate isn't low enough, and a messed-up financial system is dragging down the real economy -- is essential if we're going to avoid the worst.

The key thing, when you're in a situation like this, is realizing that normal rules don't apply. Ordinarily we'd welcome an increase in private saving; right now we're living in a world subject to the "paradox of thrift," in which private virtue is public vice. Normally we want to be careful that public funds are spent wisely; right now the crucial thing is that they be spent fast. (John Maynard Keynes once suggested burying bottles of cash in coal mines and letting the private sector dig them up -- not as a real proposal, but as a way of emphasizing the priority of supporting demand.)

Daher ist wahrscheinlich viel Evidenz über die Wirksamkeit von wirtschaftspolitischen Maßnahmen eher uninformativ zum derzeitigen Zeitpunkt. Zeitreihenanalysen die nur "normale Jahre" analysieren können nur Aussagen über normale Jahre in denen die normale Regeln gelten machen. Daher auch die Konjunktur von ökonomischen Analysen der "New Deal" Area in den USA.

Für Europa kann daher die wirtschaftspolitische Trennung von zentralisierte Geldpolitik und dezentrale Fiskalpolitik problematisch sein. Die Staaten müssen sich koordinieren und Koordination kostet Zeit, da jeder Staat ein Interesse daran hat, dass die anderen viel ausgeben, er aber weniger.