Is price stability really what we are after or are we after financial stability? Even more generally, going back over time we have tended to argue, I think correctly, that the objective of monetary policy is to create maximum sustainable economic growth, and we have argued, again I think quite correctly, that price stability is a necessary condition to reach that goal. But price stability may indeed be a proxy for something else, which I suspect is financial stability...It is by no means clear exactly how we should measure price stability, given the prospect that it will become increasingly difficult over time to define what constitutes output and prices...When we move into the 21st century, what we will try to stabilize may in effect be the purchasing power of money, however that is measured...While I am not saying that these involve issues that we need to resolve today, I suspect that we will start to confront them in 5 years or certainly within 10 years, and they may very well affect our projections going out to, say, the year 2006. I also suspect that by around the year 2006, this very tricky question may involve what we are endeavoring to stabilize and may be the focus of our policy actions. My own guess is that we are going to be dealing with asset prices, the question of nominal long-term interest rates, and probably the outlook for nominal GDP as well.