Paul Fisher explains that, in normal times, 'reserves averaging' is employed as part of the Bank's Sterling Monetary Framework (SMF) to implement the MPC's official interest rate decision each month, with commercial banks remunerated at Bank Rate if they hit a self-determined target level of reserves. But that system has been suspended since the introduction of QE in March 2009. Instead, the Bank has operated a 'floor' system, where banks are remunerated at Bank Rate on any level of reserves. Paul Fisher reviews the merit of both systems, as well as a third model, but says the Bank ".expects to return to a reserves averaging system in due course. Presumptively, that would be after increasing Bank Rate and before asset sales began - although timing and sequencing will depend on the circumstances at the time."