Risk and ambiguity in a public good game

Introduction Ambiguity is part of most of the daily life decisions. It can affect the way people deal with environmental threats, especially when they face a social dilemma. Method We run an experiment where every group of four subjects is exposed to a risk that may result in a loss for each member. Subjects must decide on the allocation of their resources between mitigation strategies that allow them to decrease the probability of a disaster occurring for the group, and adaptation strategies that allow them to reduce the magnitude of that disaster for themselves only. In a first treatment (called R isk), subjects perfectly know the probability of occurrence of the event. We introduce ambiguity with regard to that probability in a second treatment (called Amb iguity), and in a third treatment (called I nformation A cquisition), subjects have the possibility to pay to obtain information allowing them to eliminate ambiguity. Results and discussion The results show that the introduction of ambiguity has no impact on average contributions compared to the R isk treatment. However, individual decisions to mitigate or to adapt are affected by subjects' attitude toward risk and ambiguity. In more than half of the cases, subjects are willing to pay to obtain information, which argues in favor of greater dissemination of information.