Helping somebody may undermine his incentives to work. What Buchanan identified more than 25 years ago as the Samaritan's dilemma is basically a time-inconsistency problem. The paper discusses possible solutions of the dilemma such as punishment within an iterated game, reshaping the game in the...

In the Solidarity Game (Selten and Ockenfels, 1998), two "rich" persons can support a "poor" one. A strong positive correlation between one rich person's solidarity contribution and his expected contribution of the other is observed. This paper investigates the causality behind this correlation....

In Dictator Game experiments where the information status of the recipient varies we find that a certain type of donator tends to reduce his offer when the recipient has incomplete information about the pie size. This result provides new evidence on those approaches on altruism, which assume...

We examine two types of altruism and their implications for voluntary giving. Philanthropists are altruists who wish to enhance the well-being of others, while individuals with merit-good preferences only wish to further the consumption of certain merit goods by others. Philanthropic donors...

In social dilemmas, there is tension between cooperation that promotes the common good and the pursuit of individual interests. International climate change negotiations provide one example: although abatement costs are borne by individual countries, the benefits are shared globally. We study a...

The equilibrium outcome of a strategic interaction between two or more people may depend on the weight they place on each other's payoff. A positive, negative or zero weight represents altruism, spite or complete selfishness, respectively. Paradoxically, the real, material payoff in equilibrium...

We test the proposition that individuals may experience a self-control conflict between short-term temptation to be selfish and better judgment to act pro-socially. Using a dictator game and a public goods game, we manipulated the likelihood that individuals identified self-control conflict, and...

In recent years a large number of experimental studies have documented the existence of strong reciprocity among humans. Strong reciprocity means that people willingly repay gifts and punish the violation of cooperation and fairness norms even in anonymous one-shot encounters with genetically...

We investigate a setting in which members of a population, bifurcated into a majority and a minority, transact with randomly matched partners. All members are uniformly altruistic, and each transaction can be carried out cooperatively or through a market mechanism, with cooperative transactions...

Recent bargaining experiments demonstrated an impact of anonymity and incomplete information on subjects' behavior. This has rekindled the question whether fair behavior is inspired by regard for others or is explained by external forces. To test for the importance of external pressure we...