In this paper, an economy is analyzed where one group of agents, the altruists, cares about the well-being of another group of agents, the recipients. It is asked how changes in the size of these groups affect the altruists' charitable giving in the Nash equilibrium. I show that a pure group...

Using the traditional model of voluntary public good provision, it is shown that an expansion of group size exacerbates free riding tendencies as long as private consumption and the public good are strictly normal and weak gross substitutes. This result generalizes a previous Cobb-Douglas...