To examine the effect of group size on the stability of prosocial behavior we used standard one-shot public good experiments with two and four subjects, which were conducted repeatedly three times at intervals of one week. Partner and stranger treatments were employed to control for group...

The dynamics of behavior observed in standard public-good experiments can be explained by imperfect conditional cooperation combined with social learning (Fischbacher and Gächter, 2010). But it is unclear what determines first-round contributions. We argue that first-round contributions depend...

Since Mancur Olson's "Logic of collective action" it is common conviction in social sciences that in large groups the prospects of a successful organization of collective actions are rather bad. Following Olson's logic, the impact of an individual's costly contribution becomes smaller if the...