Transshipments between (counter-) altruistic retailers

We investigate altruistic behavior in an inventory transshipment system of two independent newsvendor retailers. We prove concavity of the objective function and existence and uniqueness of Nash equilibrium. Retailers' orders are increasing (decreasing) in altruism for low (high) transshipment prices and the coordinating transshipment price is not affected by altruism. Unlike self-interested retailers, altruistic retailers may decide in a way such that transshipments lead to lower expected profits than without transshipment.We find that increasing (counter-)altruism (harms) benefits supply chain performance.