The cardiovascular risks for Vioxx found in tests after it was on the market were known for some time before a warning was added to the label following extensive negotiations between the agency and the drug sponsor. That delay led to calls for drug reform. This paper examines why pre-market...

The prisoner's dilemma (PD) is arguably the most important model of social dilemmas, but our knowledge about how a PD’s material payoff structure affects cooperation is incomplete. In this paper we investigate the effect of variation in material payoffs on cooperation, focussing on one-shot PD...

The prisoner's dilemma (PD) is arguably the most important model of social dilemmas, but our knowledge about how a PD's material payoff structure affects cooperation is incomplete. In this paper we investigate the effect of variation in material payoffs on cooperation, focussing on one-shot PD...

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...