We experimentally investigate cooperation in privileged groups which according to Olson (1965) are groups in which at least one member has an incentive to supply a positive amount of the public good. More specifically, we analyze group member heterogeneity with respect to two dimensions:...

One lingering puzzle is why voluntary contributions to public goods decline over time in experimental and real-world settings. We show that the decline of cooperation is driven by individual preferences for imperfect conditional cooperation. Many people's desire to contribute less than others,...

There is by now ample evidence from laboratory experiments that individuals exhibit "prosocial" or "other-regarding" preferences. However, a key question is whether the importance of other-regarding preferences documented in the laboratory can be readily generalized to draw conclusions about the...

We provide a framework to uncover behavioural mechanisms driving potential cross-societal differences in voluntary cooperation. We deploy our framework in one-shot public goods experiments in the US and the UK, and in Morocco and Turkey. We find that cooperation is higher in the US and UK than...

We examine the effect of payoff variations on cooperation in one-shot prisoner's dilemma games. We focus on three factors: risk, temptation, and efficiency, which we vary as orthogonal treatments. We find that temptation has the largest impact on cooperation. Temptation directly deters...

We experimentally examine how the incentive to defect in a social dilemma affects conditional cooperation. In our first study we conduct online experiments in which subjects play eight Sequential Prisoner's Dilemma games with payoffs systematically varied across games. We find that few second...

We experimentally examine how incentives affect conditional cooperation (i.e., cooperating in response to cooperation and defecting in response to defection) in social dilemmas. In our first study, subjects play eight Sequential Prisoner's Dilemma games with varying payoffs. We elicit second...

We examine how conditional cooperation is related to the material payoffs in a Sequential Prisoner's Dilemma experiment. We have subjects play eight SPDs with varying payoffs, systematically varying the material gain to the second-mover and the material loss to the first-mover when the...

We study two generic versions of public goods problems: in Provision problems, the public good does not exist initially and needs to be provided; in Maintenance problems, the public good already exists and needs to be maintained. In five lab and online experiments (n=2,584), we document a robust...

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...