Task influences on judgemental forecasting

This study investigates the effect of imminence, time duration and subjective desirability on judgemental forecasts. People were found to be more sure of specified events happening in a one-month time period subsequent to an imminent one-month period. The time duration of a forecast period, one month versus two months, had no effect on forecasting response and performance and any effect of the subjective desirability of an event on its perceived likelihood was negligible. Although evidence of the consistency of individual forecasting response and performance was obtained, individual measures of coherence in probability assessment were not related to forecasting performance. A measure of the subjective difficulty of the forecasting task was not related to forecasting performance, indicating that attempts to re-scale forecasting responses to improve forecasting performance on the basis of subjective difficulty are inappropriate.