Power leads to greater errors in forecasts, according to new research led by social psychologist Dr Mario Weick at the University of Kent.

The research, to be published by the Journal of Experimental Social Psychology, shows that when people feel powerful they become more optimistic and less accurate in predicting the completion time of forthcoming tasks. The research examined for the first time the planning behaviour of powerful people and found that power drastically reduced the accuracy of forecasts with error rates soaring up to 70%.

Dr Weick, a Research Fellow at the University's School of Psychology, explained: 'Time is a crucial factor in people's everyday lives. Whether they are teachers, policy makers or engineers, people routinely plan their work and estimate the time it will take to accomplish tasks. Interestingly, people often underestimate the time it takes to accomplish tasks. This bias is known as the planning fallacy and derives from a too narrow focus on the envisaged goal. The more people focus on what they want to achieve, the more they tend to neglect impediments, previous experiences and task subcomponents that are not readily apparent. As a result, time predictions are often inaccurate and too optimistic. Power tends to increase people's focus on intended outcomes. Although this can be beneficial, in the context of time planning we reasoned that power would lead to greater error in forecasts.'

The researchers carried out four experiments, showing that when people felt powerful they tended to underestimate more the time it took to accomplish various tasks, ranging from mundane activities to important projects. Dr Weick said: 'What appears to underlie these effects is not so much that people in power have greater faith in their abilities or that they see things through rose-tinted glasses, power affects what people focus on when they plan the future, and this seems to be the root of the greater bias in powerful individuals' time predictions.'

The findings suggest that people who are in charge and deciding on courses of action (eg policy makers) are more at risk to fall prey to biases in their forecasts. The research also proposes ways to alleviate the biasing effects of power. Specifically, forecasting accuracy could be improved by using techniques that draw people's attention to information that lies outside their focal goal. Moreover, changing the power structure of planning committees could also be a way to render forecasts more accurate (eg by assigning greater weight to the predictions of individuals who do not have power).

The project was funded by the Economic and Social Research Council (ESRC), the UK's leading agency for research funding and training in economic and social sciences.