Leijonhufvud in his piece on VOX challenges two central bank doctrines:

1. inflation targeting;

This strategy failed in the United States. The Federal Reserve lowered the federal funds rate drastically in an effort to counter the effects of the dot.com crash. In this, the Fed was successful. But it then maintained the rate at an extremely low level because inflation, measured by various variants of the CPI, stayed low and constant. In an inflation targeting regime this is taken to be feedback confirming that the interest rate is “right”. In the present instance, however, US consumer goods prices were being stabilised by competition from imports and the exchange rate policies of the countries of origin of those imports. American monetary policy was far too easy and led to the build-up of a serious asset price bubble, mainly in real estate, and an associated general deterioration in the quality of credit. The problems we now face are in large part due to this policy failure.

2. independence

When monetary policy comes to involve choices of inflating or deflating, of favouring debtors or creditors, of selectively bailing out some and not others, of allowing or preventing banks to collude, no democratic country can leave these decisions to unelected technicians. The independence doctrine becomes impossible to uphold.

His argument is quite interesting.