Donors may often not be sure whether a recipient really deserves their help. Does this uncertainty deter generosity? In … an experiment we find that, to the contrary, under most specifications of uncertainty, dictators give more, compared with … the donation the same dictator makes to a recipient they know to have the expected value of the endowment with certainty …

substantially more than men, but also show an economically significant positive correlation between risk tolerance and donation …

considerations under uncertainty might be fundamentally different from those when no uncertainty is present. Furthermore, we find …

uncertainty on an individual's decision to commit a violation are very difficult to observe in field data. We use a roadway …) uncertainty about the enforcement regime yields a large reduction in violations committed, and (c) people are much more likely to … behavioral theory of deterrence under uncertainty …

A donation may have ambiguous costs or ambiguous benefits. Behavior in a laboratory experiment suggests that …-driven behavior is more pronounced when the costs of a donation - rather than its benefits - are ambiguous. However, the importance of … excuse-driven behavior is comparable under ambiguity and under risk. Individuals exploit any type of uncertainty as an excuse …