The following article reproduces a paper by Peter Nicholl and David Archer which won a Special Merit Award in the International Amex Bank Review Essay Awards in Memory of Robert Marjolin. It is based on a speech given by Peter Nicholl in October 1991 to a Conference in Sydney, oganised by Macquarie University. Because of the time that had elapsed since the original presentation, a postscript was added at the end of the aticle to update the discussion on experience under the Reserve Bank's monetary policy framework.