We study cooperation within and between groups in the laboratory, comparing treatments in which two groups have previously been (i) in conflict with one another, (ii) in conflict with a different group, or (iii) not previously exposed to conflict. We model conflict using an inter-group Tullock...

I test the effect of multiple pivotal players on unfair choices in a setup with a leader and two followers deciding on whether to expropriate the payoff of a group member. Comparing unanimity decisions to individual decisions within the group, I find that leaders are fairer in the unanimity rule...