In our model, an agent produces an outcome by a costly effort and then distributes it among heterogeneous users. The agents̕ payoff is the weighted sum of the users ̕shares and the coefficient reflecting their heterogeneity. When the agent neglects users ̕heterogeneity the game leads to an...

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....