Predicting the World Cup 2002 in soccer: Performance and confidence of experts and non-experts

This paper investigates the forecasting performance and confidence of experts and non-experts. 251 participants with four different levels of knowledge of soccer (ranging between expertise and almost ignorance) took part in a survey and predicted the outcome of the first round of World Cup 2002. The participating experts (i.e., sport journalists, soccer fans, and soccer coaches) and the non-experts were found to be equally accurate and better than chance. A simple prediction rule that followed world rankings outperformed most participants. Experts overestimated their performance and tended to be overconfident, while the opposite tendency was observed for the participants with limited knowledge. Providing non-experts with information did not improve their performance, but increased their confidence.