We report experimental evidence on the effect of observability of actions on bank runs. We model depositors' decision-making in a sequential framework, with three depositors located at the nodes of a network. Depositors observe the other depositors' actions only if connected by the network. Theoretically, a sufficient condition to prevent bank runs is that the second depositor to act is able to observe the first one's action (no matter what is observed). Experimentally, we find that observability of actions affects the likelihood of bank runs, but depositors' choice is highly influenced by the particular action that is being observed. Depositors who are observed by others at the beginning of the line are more likely to keep their money deposited, leading to less bank runs. When withdrawals are observed, bank runs are more likely even when the mere observation of actions should prevent them.Keywords: bank runs, social networks, coordination failures, experimental evidence. JEL Classification: C70, C91; D80; D85; G21We are indebted to Luis Moreno-Garrido for his contribution to the experimental design and to Coralio Ballester, Todd Keister, Raúl López, Giovanni Ponti, Miguel Sánchez-Villalba and Adam Sanjurjo for useful comments. We would also like to thank Ivan Arribas and Lola Collado for helpful advices in the econometric analysis. Finally, this paper has benefitted from suggestions provided by the anonymous reviewers, seminar and conference participants at

We introduce non-enforceable property rights over a bargaining surplus in a dictator game with production, where the agent's effort is differentially rewarded and subsequently determines the size of the surplus. Using experimental data, we elicit individual preferences over the egalitarian, accountability and libertarian principles and provide evidence to support the inability of these justice principles to individually account for the observed behavior. We show that the justice principle that can be used to explain dictators' choices depends on whether dictators are paid more or less than recipients for their effort. Our findings suggest that dictators do employ justice principles in self-serving ways and choose in each context the justice principle that maximizes their financial payoffs.

Mechanisms supporting human ultra-cooperativeness are very much subject to debate. One psychological feature likely to be relevant is the formation of expectations, particularly about receiving cooperative or generous behavior from others. Without such expectations, social life will be seriously impeded and, in turn, expectations leading to satisfactory interactions can become norms and institutionalize cooperation. In this paper, we assess people’s expectations of generosity in a series of controlled experiments using the dictator game. Despite differences in respective roles, involvement in the game, degree of social distance or variation of stakes, the results are conclusive: subjects seldom predict that dictators will behave selfishly (by choosing the Nash equilibrium action, namely giving nothing). The majority of subjects expect that dictators will choose the equal split. This implies that generous behavior is not only observed in the lab, but also expected by subjects. In addition, expectations are accurate, matching closely the donations observed and showing that as a society we have a good grasp of how we interact. Finally, correlation between expectations and actual behavior suggests that expectations can be an important ingredient of generous or cooperative behavior.