Type-projection, pro-social behavior, and a public good game

People tend to overestimate how similar others are to themselves. Such projection onto others has broad consequences: we focus on those for pro-social behavior, modeled as a standard public-good contribution game. We find that contributions of sufficiently rich players decrease with projection, because they believe more players are similarly rich and hence overestimate others’ contributions. Conversely, projection increases poor players’ contributions because they believe more players are similarly poor and hence underestimate others’ contributions. In our simple setup, the effect of projection on overall contributions is negative. Our results contribute to the debate on whether the rich are less“generous” than the poor.