Inside Buchanan's Samaritan's Dilemma: altruism, strategic courage and ethics of responsibility

The Samaritan's Dilemma has largely been investigated, frequently by assuming that Samaritans help recipients out of altruism. Yet, Buchanan did not make any behavioral assumption regarding the Samaritan's motives. In this paper, we explicitly introduce this assumption in Buchanan's original model and analyze how it changes the nature of the game. We show that altruism alone does not explain the Dilemma. A parameter that captures the disutility the Samaritan feels when helping someone who does not reciprocate her benevolence must be introduced to make sense of the different version of Buchanan's Samaritan's Dilemma. We also show that the Samaritan's Dilemma is an evolutionary stable outcome, which confirms Buchanan's intuitions. Finally, a third important point put forward in the paper is that the more altruistic are the Samaritans, the less likely it is that they will show the kind of strategic courage envisaged by Buchanan, which is one of the most important traits Samaritans should display to avoid being trapped in a Dilemma.