I personally think giving central banks the power to decide when to change interest rates (independent central banks, or ICBs) is a sensible form of delegation, provided it is done right. I know a number of the people who read this blog disagree. Sometimes, however, arguments against ICBs seem to me pretty weak. This is a shame, because there is I believe quite a strong case against ICBs. Let me set it out here.
In the post war decades there was a consensus, at least in the US and UK, that achieving an adequate level of aggregate demand and controlling inflation were key priorities for governments. That meant governments had to be familiar with Keynesian economics, and a Keynesian framework was familiar and largely accepted in public discourse. Here I am using Keynesian in its wide sense, such that Milton Friedman was also a Keynesian (he used a Keynesian theoretical model).
A story some people tell is that this all fell apart in the 1970s with stagflation. In the sense I have defined it, that is wrong. The Keynesian framework had to be modified to deal with those events for sure, but it was modified successfully. Attempts by New Classical economists to supplant Keynesian thinking in policy circles failed, as I note here.
The more important change was the end of Bretton Woods and the move to floating exchange rates. That was critical in allowing the focus of demand management to shift away from fiscal policy to monetary policy. The moment that happened, it allowed the case for delegation to be made. Academics talked about time inconsistency and inflation bias, but the more persuasive arguments were also simpler. Anyone who had worked in finance ministries knew that politicians were often tempted and sometime succumbed to using monetary policy for political rather than economic ends, and the crude evidence that delegation reduced inflation seemed strong.
That allowed the creation of what I have called the consensus assignment. Demand management should be exclusively assigned to monetary policy, operated by ICBs pursuing inflation targets, and fiscal policy should focus on avoiding deficit bias. The Great Moderation appeared to vindicate this consensus.
However the consensus assignment had an Achilles Heel. It was not the global financial crisis (which was a failure of financial regulation) but the Zero Lower Bound (ZLB) for nominal interest rates. Although many macroeconomists were concerned about this, their concern was muted because fiscal action always remained as a backup. To most of them, the idea that governments would not use that backup was inconceivable: after all, Keynesian economics was familiar to anyone who had done Econ 101.
That turned out to be naive. What governments and the media remembered was that they had delegated the job of looking after the economy to the central bank, and that instead the focus of governments should be on the deficit. Macroeconomists should have seen the warning signs in 2000 with the creation of the Euro. There monetary policy was taken away from individual union governments, but still the Stability and Growth Pact was all about reducing deficits with no hint at any countercyclical role. When economists told politicians in 2009 that they needed to undertake fiscal stimulus to counteract the recession, to many it just felt wrong. To others growing deficits presented an opportunity to win elections and cut public spending.
Macroeconomists were also naive about central banks. They might have assumed that once interest rates hit the ZLB, these institutions would immediately and very publicly turn to governments and say we have done all we can and now it is your turn. But for various reasons they did not. Central banks had helped create the consensus assignment, and had become too attached to it to admit it had an Achilles Heel. In addition some economists had become so entranced by the power of Achilles that they tried to deny his vulnerability.
From 2010, as austerity began, the damage caused by ICBs became clear. One ICB, the ECB, refused to back its own governments and allowed a Greek debt financing crisis to become a Eurozone crisis. The subsequent obsession with austerity happened in part because governments no longer saw managing demand as their prime responsibility, and the agent they had contracted out that responsibility to failed to admit it could no longer do the job. But it was worse than that.
Economists knew that the government could always get the economy out of a demand deficient recession, even if it had a short term concern about debt. The fail safe tool to do this was a money financed fiscal expansion. This fiscal stimulus paid for by the creation of money was why the Great Depression could never happen again. But the existence of ICBs made money financed fiscal expansions impossible when you had debt obsessed governments, because neither the government nor the central bank could create money for governments to spend or give away. Central banks were happy to create money, but refused to destroy the government debt they bought with it, and so debt obsessed governments embarked on fiscal consolidation in the middle of a huge recession.
The slow and painful recovery from the Great Recession was the result. Economists did not get the economics wrong. Money financed fiscal expansion does get you out of a recession with no immediate increase in debt. But by encouraging the creation of ICBs, economists had helped create both the obsession with austerity and an institutional arrangement that made a recession busting policy impossible to enact.
I have tried to put the argument as strongly as I can. I think it is an argument that can be challenged, but that will only happen if macroeconomists first admit the problem it exposes.