Mervyn King. Image by Getty.

A few weeks ago, the big central banks were calmly embarking on their “exit” strategies from unconventional monetary accommodation. Then the global economy slowed but for a while inflation remained too high for the Fed or the ECB to consider further easing. Their hands were tied until inflation peaked. Recognising this, markets collapsed. But now that there are some tentative signs of inflation subsiding, the central banks are rediscovering their ammunition stores.

There are basically three types of action that they are considering. In order of orthodoxy, and stealing some of Mervyn King’s terminology, here is a taxonomy of possible measures:

1. Conventional liquidity injections

This is safe territory for the central banks, and they are willing to act swiftly and decisively if necessary. Yesterday’s injections of dollar liquidity into the European financial system are a case in point. Some European banks, especially those in France, were finding it very difficult to raise dollar financing, which they needed in order to pay down earlier dollar borrowings, and to make loans to customers in dollars. The resulting strains in the money markets were undermining confidence in the ability of these banks to remain liquid, and markets were increasingly unwilling to accept their credit. This presented a classic case for the ECB to inject liquidity, using conventional currency swap arrangements to raise dollars from the Fed. Although the ECB will incur a minimal amount of currency risk in the process, and will also incur some credit risk (which will be collateralised), this is very much business as usual for any central bank, as it was in 2008.