BIS Review 36/2009  3  •  Dispersion of board members’ point forecasts (eg Federal Reserve),  •  Confidence intervals based on past forecast errors and the judgement of board members (eg Bank of England) and  •  Dispersion measures derived from past forecast errors, such as the mean of absolute past forecast errors (eg Bundesbank and, until recently, Eurosystem staff projections).
The computation of Eurosystem staff projection ranges was changed in autumn of last year. Instead of deriving them from past forecast errors, these ranges are now based on Bayesian Vector Autoregressions (BVARs) that account for shock and estimation uncertainty. The ranges are conditional on assumptions on several exogenous variables such as oil prices, exchange rates and foreign demand.