When one thinks about the distant future – that is, the period beyond the influence of the current set of cyclical factors – one tends to think that interest rates will tend toward a level that reflects the rate of return on investment, and hence the potential output growth of the economy. Potential output growth matters a great deal for monetary and macroprudential policy. In the long run it determines the rate at which the economy can grow without generating abovetarget inflation, and it determines the rate of income growth in the medium term, and hence the sustainable level of debt today. During the financial crisis, we rediscovered the fact that recessions accompanied by financial crises tend to be followed by a sustained fall in the level of potential output. 13 The only silver lining was that although the level of potential output tended to be permanently lower, the growth rate could be expected to recover. However, if the current yield curve can be interpreted as an indicator of financial market participants’ expectations of the return on investment in the long term, it suggests they are  11  Barro (2006) shows that the potential for rare economic disasters can explain low risk-free rates  12  This can be broadly defined to include the higher cost of financial intermediation  13  IMF (2009)  4  BIS central bankers’ speeches  sceptical that potential output growth can even return to pre-crisis norms.
The macroeconomic projections by Eurosystem staff constitute an important input into the monetary policy decisions, because they are a way of organising a large amount of information and they help to create a consistent picture of possible future developments. However, the economic projections cannot encompass or even reflect all the complexities, conditioning factors, nuances and the multi-dimensional nature of a comprehensive assessment of the risks to price stability on which monetary policy decisions need to be based. While the information synthesised from various indicators serves as an important input into the decision-making process, the Governing Council of the ECB does not take decisions only on the basis of projections. The Governing Council’s “judgement” must eventually come into play in order to assess the likelihood of the alternative scenarios suggested by the economic analysis. This is particularly important when it is quite unclear how a certain situation will evolve, as is the case sometimes with sharp movements in asset prices. Related to this, attempts to base monetary policy decisions solely on inflation forecasts would involve significant limitations. Notably, they would entail an inefficient use of information, since every forecast, or any composite index of indicators, is based on one possible scenario and one combination of assumptions. In the end, monetary policy requires judgement on the part of the policy-maker to assess  BIS Review 67/2004  5  not only the plausibility of all possible scenarios, but also the nature of the shocks and the best policy reaction in order to deal with this uncertain environment.