IV. Sequencing and the “Costs” of Low Interest Rates  The forms of monetary stimulus described above can be used once the overnight rate has already been driven to zero or as a way of driving the overnight rate to zero. However, a central bank might choose to rely on these alternative policies while maintaining the overnight rate somewhat above zero.
For example, monetary policy makers might attempt to influence market expectations of future short rates as an alternative to changing the current setting of the overnight rate. Another possibility is to try  4  BIS Review 3/2004  to affect term premiums, expectations of future rates, or both, by changing the composition of securities held by the central bank.