INCOMPLETE INFORMATION AND TIMING IN THE VOLUNTEERS DILEMMA - A COMPARISON OF 4 MODELS

We analyze the supply of a public good that can be privately produced at costs smaller than the benefits. Without a coordinating mechanism, the selection of a volunteer poses a social dilemma. By varying two co nditions, we obtain four scenarios. First, we distinguish whether or n ot players observe each other's behavior. Under the condition that beh avior is observed, strategies involve timing decisions, namely how lon g to wait before volunteering, hoping that someone else volunteers fir st, but incurring costs for delayed production. If behavior cannot be observed, players effectively choose simultaneously, and rational play ers will either volunteer immediately or not at all. Second, we distin guish complete information with respect to the costs and benefits of t he other players from incomplete information. For each of the four sce narios, we discuss a game theoretic model that assumes (ex ante) symme trical costs and benefits. Remarkably, the probability that a player v olunteers may increase with the degree of uncertainty. Moreover, in co ntrast with the complete information models, if uncertainty is suffici ently high, the probability that the collective good is produced may a ctually increase with group size. Finally, the four scenarios are rank ed by the extent to which they generate favorable incentives for the p roduction of the public good.