Perils of unconventional monetary policy

Unconventional monetary policy, by relaxing restrictions on the composition of the balance sheet of the central bank, compromises control over the stochastic path of inflation; or, in open economies, over the stochastic path of exchange rates. If the composition of the balance sheet is unrestricted then the path of inflation is indeterminate. This is the case under pure quantitative easing, where the target is the size of real money balances. In contrast, credit easing policies restrict the composition of the portfolio by targeting a specific expansion in the maturity profile of bonds bought, and thus can implement a determinate path of inflation. The composition of the portfolios traded by monetary-fiscal authorities also determines premia in asset and currency markets.