Subjective probabilities: psychological theories and economic applications

Abbigail J. Chiodo, Massimo Guidolin, Michael T. Owyang, and Makoto Shimoji> Real-life decisionmakers are often forced to estimate the likelihood of uncertain future events. Usually, economists assume that these agents behave in a fully rational manner, employing statistical rules to assess probabilities, and that they maximize expected utility. Psychological studies, however, have shown that people do not tend to behave as rational models would predict. The authors review three rules of thumb taken from the psychology literature that people rely on when assessing the likelihood of uncertain events. The authors construct a simple model of belief formation that incorporates these rules and then present one formal and three illustrative applications showing how these psychological phenomena cause deviations from anticipated economic outcomes.