As we move forward in time, as is natural, the relative importance of the three policy tools will change, and the main tool for shaping the policy stance will become the path of our key interest rates and the forward guidance about their likely evolution. Today, by and large, markets quantify the “well past” interval as ‘up to next spring’.
But at some point that ‘well past’ indication will not be sufficient any longer to give the public enough information about the most likely outlook for our policy. Once you stop net asset purchases the signaling aspect of the APP disappears and you therefore have to be much more precise about the future path of the short term rates.