large body of research demonstrates the power of “reciprocity” for inducing cooperation: When others know that you have … they think others are also cooperating; and people can develop habits of cooperation that shape their default inclinations …

dampens cooperation, though only slightly. Surprisingly, externalities are immaterial. If we control for beliefs, they even … we add beliefs as a control variable, we only find that externalities enhance cooperation, even if gains from collusion … cooperation, undercutting is defection. Jointly, competitors are better off if both are faithful to a cartel. Individually, profit …

externality. A within-subjects measure of reticence to impose harm does not explain cooperation. But the externality makes … participants more pessimistic. However conditional on their beliefs participants are more, not less cooperative if cooperation …

competition (lottery contest) and one that encourages cooperation (public good game). We find that simultaneous participation in … strategic uncertainty and path-dependence across games. Our design allows us to compare preferences for cooperation and …

conditional cooperation prioritizing local level externalities. Our findings demonstrate how individuals adjust their behavior … examines the nature of human behavior in a multilevel social dilemma game with positive provision externalities to local and …

, and explains the degree of cooperation by a combination of five motives: the size of gains from cooperation, expectations …

, the optimal mechanism involves either one or two voting rounds. We show that procedural efficiency cannot be achieved by …

is able to sustain cooperation in groups even when it is observed only in the end of the interaction sequence. Our …. Providing both unobserved and observed punishment strongly enhances cooperation within groups - strikingly, even with less …