Debiasing forecasts: how useful is the unbiasedness test?

A number of studies have demonstrated the improvements in accuracy that can result from correcting judgmental forecasts to remove systematic bias. It has been suggested that the ‘unbiasedness test’, based on the F-distribution, should be employed to determine when to apply correction to forecasts. The effectiveness of using the test for this purpose was investigated under conditions where its underlying assumptions were valid. The results suggest that, even under these conditions, the use of the test is unlikely to be advisable in most practical contexts and that a policy of always correcting forecasts is preferable.