Simultaneous inter- and intra-group conflicts

This paper models the trade-off between production and appropriation in the presence of simultaneous inter- and intra-group conflicts. The model exhibits a ‘group cohesion effect’: if the contest between the groups becomes more decisive, the players devote fewer resources to the intra-group conflict. Moreover, there is also a ‘reversed group cohesion effect’: if the intra-group contests become less decisive, the players devote more resources to the inter-group contest. The model also sheds new light on normative questions. I derive exact conditions for when dividing individuals into more groups leads to more productive and less appropriative activities. Moreover, I show that there is an optimal size of the organization which is determined by a trade-off between increasing returns to scale in production and increasing costs of appropriative activities. I want to thank Paul Heidhues, Kai Konrad, Thomas Kittsteiner, Klaas Staal, an anonymous referee, and in particular Dan Kovenock for very helpful comments and suggestions. Any remaining errors are mine. Financial support from the Deutsche Forschungsgemeinschaft through SFB/TR 15 is gratefully acknowledged.