In short, there are two arguments for this: (i) engaging in such behaviour – let’s call it “leaning against the wind” – in situations when an asset price is changing due to non-fundamentals can dampen the effects of the unmotivated price change on the real economy and thereby prevent an inefficient allocation of resources; (ii) if the market knows that the central bank engages in “leaning against the wind” activities the probability will fall of non-fundamental price changes arising in the first place. The key issue here is, of course, identifying price changes that are driven by nonfundamentals. This problem cannot be overly emphasized. But difficult or not, it is an issue that central banks cannot ignore. If prices of houses or other assets are partly driven by factors that are hard to explain and that are believed to give rise to inefficient allocations and risks of large fluctuations in real economic activity and inflation, such events will, in one way or another, find their way into our thinking about monetary policy. Extending the forecasting horizon In practice, most inflation targeting central banks have chosen to adopt forecast horizons of two to three years, at least in external communication and official documents. In this environment, the idea that a central bank can need to extend the horizon over which it constructs inflation and output forecasts is one that has been heard from many central banks.
Measures of underlying inflation that exclude the effects on CPI of our own interest-rate changes have been closer to the target of 2 per cent, as have inflation expectations (see Figure 1). BIS Review 96/2007  1  Figure 1: Inflation Expectations in Sweden Money market agent expectations, annual percentage change 5  5 Inflation expectations CPI  4  4  3  3  2  2  1  1  0  0  -1  -1  -2 1994  -2 1996  1998  2000  2002  2004  2006  2008  2010  2012  Sources: Prospera Research AB and Statistics Sweden  Figure 2: Real estate prices Index 1996 4th quarter = 100 350  350  Australia UK United States Sweden  300  300  250  250  200  200  150  150  100  100  50  50  0  0 97  98  99  00  01  02  03  04  05  06  07  Sources: Australian Bureau of Statistics, Nationwide, OFHEO and Statistics S eden  Since my remarks are to be on the role that house prices have played in Swedish monetary policy in recent years the following should be noted too. Since 1996 nominal house prices in Sweden have more than doubled (the increase is around 140 per cent, see Figure 2) and the average price for a coop condominium has risen even more.