Understanding whether the size of the interacting group has an effect on cooperative behavior has been a major topic of debate since the seminal works on cooperation in the 1960s. Half a century later, scholars have yet to reach a consensus, with some arguing that cooperation is harder in larger...

How can we maximize the common good? This is a central organizing question of public policy design, across political parties and ideologies. The answer typically involves the provisioning of public goods such as fresh air, national defense, and knowledge. Public goods are costly to produce but...

In the last few decades, numerous experiments have shown that humans do not always behave so as to maximize their material payoff. Cooperative behavior when non-cooperation is a dominant strategy (with respect to the material payoffs) is particularly puzzling. Here we propose a novel approach to...

Research in behavioral economics suggests that in addition to their traditional incentive effects, formal control systems can influence psychological motivations. We extend this literature by demonstrating experimentally that formal controls directly influence people’s sense of what behaviors...

We study the evolution of cooperation in spatial public goods games with four competing strategies: cooperators, defectors, punishing cooperators, and punishing defectors. To explore the robustness of the cooperation-promoting effect of costly punishment, besides the usual strategy adoption...

We study the evolution of cooperation under the assumption that the collective benefits of group membership can only be harvested if the fraction of cooperators within the group, i.e., their critical mass, exceeds a threshold value. Considering structured populations, we show that a moderate...

We study the evolution of cooperation in spatial public goods games where, besides the classical strategies of cooperation (C) and defection (D), we consider punishing cooperators (PC) or punishing defectors (PD) as an additional strategy. Using a minimalist modeling approach, our goal is to...

Several experiments show that feedback transmission mechanisms mitigate opportunistic behavior in social dilemmas. The source of this effect, especially in a repeated interaction, nonetheless remains obscure. This study provides a novel empirical testbed for channels by which feedback may affect...

This paper examines countries' free-riding in international environmental agreements (IEA) when, first, the treaty is non-enforceable, and second, countries do not have complete information about other countries' noncompliance cost. We analyze a signaling model whereby the country leading the...