We study how conflict in contest games is influenced by rival parties being groups and by group members being able to punish each other. Our motivation stems from the analysis of socio-political conflict. The theoretical prediction is that conflict expenditures are independent of group size and...

Power indices suggest that adding new members to a voting body may affect the balance of power between the original members even if their number of votes and the decision rule remain constant. Some of the original members may actually gain, a phenomenon known as the paradox of new members. We...

In this study, we use an allocation game to study the effects of group identity and group size on in-group favouritism when the person's own payoff is not affected by her decision. We first show that in a triadic setting when the subjects are asked to allocate a fixed amount of resource between...

Many situations in the social and economic life are characterized by rivalry and con ict between two or more competing groups. Warfare, socio-political con icts, political elections, lobbying, and R&D competitions are all examples of inter-group con icts in which groups spend scarce and costly...

We study the effects of voluntary participation on cooperation in collective action problems. Voluntary participation may foster cooperation through a mechanism of assortative selection of interaction partners based on false consensus bias, or through a mechanism whereby the decision to not...

We study the effect of group size on cooperation in voluntary contribution mechanism games. As in previous experiments, we study four- and eight-person groups in high and low marginal per capita return (MPCR) conditions. We find a positive effect of group size in the low MPCR condition, as in...