Emotions, competence and confidence in choice under uncertainty

This paper presents the results of two experiments testing reaction to risk and uncertainty of a sample of 66 Italian university students. Risky prospects were based on games of chance, while uncertain lotteries were based on the forthcoming results of either the May 2001 Italian general political election or the June 2004 election for the European Parliament. We computed decision weights for risk and uncertainty; we also collected data as regards the subjects? degree of belief, expressed by probability judgements, for the same uncertain events. Our results show that the subjects? behaviour is consistent with expected utility theory as regards risk, but not under uncertainty. In particular, our subjects show a strong superadditivity in the decision weights and the possibility effect (lower subadditivity) is stronger than the certainty effect (upper subadditivity). There is also evidence that emotions, actual competence and confidence positively affect the possibility effect, whereas they do not have any influence on the certainty effect, reinforcing the lack of symmetry between the two effects