Detectability of the negative event: effect on the acceptance of pre- or post-event risk-defusing actions.

In risky decision situations, many decision makers search for risk-defusing operators (RDOs). An RDO is an action intended by the decision maker to be performed additionally to a specific alternative and is expected to decrease the risk. Pre-event RDOs (e.g., vaccination) have to be applied before a negative event (e.g., infection) occurs. Post-event RDOs do not need to be initiated before and unless the event happens (e.g., medical treatment). For the successful application of Post-event RDOs, the negative event must be detected in time. Two experiments investigated the effect of uncertainty in the detection of the negative event. In Experiment 1, only a small minority of subjects noted this uncertainty without a cue, and even with cue, only a minority actively searched for probability information. In Experiment 2, the probability for correctly detecting the negative event was varied. When detection was certain, most subjects chose the alternative with a Post-event RDO, whereas this percentage decreased significantly with decreasing probability of correct detection. Also, in the conditions with a more extreme negative outcome, less decision makers chose the alternative with the Post-event RDO. Copyright 2002 Elsevier Science B.V.