Many types of economic and social activities involve significant behavioral complementarities (peer effects) with neighbors in the social network. The same activities often exert externalities that cumulate in "stocks" affecting agents' welfare and incentives. For instance, smoking is subject to...

Among residents of an informal housing area in Cairo, we examine how dictator giving varies by the social distance between subjects - friend versus stranger - and by the anonymity of the dictator. While giving to strangers is high under anonymity, we find - consistent with Leider et al. (2009) -...

We investigate experimentally the underlying motivations and individual differences with regard to the participation in between-group conflict in nested social dilemmas. In our nested social dilemmas, the collective is divided into two groups, and individuals allocate tokens between a private, a...