EFFICIENT USE OF INFORMATION IN THE FORMATION OF SUBJECTIVE INDUSTRY FORECASTS

The paper considers the use of information by a panel of expert industry forecasters, focusing on their information‐processing biases. The panel forecasts construction output by sector up to three years ahead. It is found that the biases observed in laboratory experiments, particularly ‘anchoring’, are observable. The expectations are formed by adjusting the previous forecast to take new information into account. By analysing forecast errors it is concluded that the panel overweight recently released information and do not understand the dynamics of the industry. However, their forecasts, both short and long term, are better than an alternative econometric model, and combining the two sources of forecasts leads to a deterioration in forecast accuracy. The expert forecasts can be ‘de‐biased’, and this leads to the conclusion that it is better to optimally process information sources than to combine (optimally) alternative forecasts. Copyright © 1991 John Wiley & Sons, Ltd.