We study the stability of voluntary cooperation in response to varying rates at which a group grows. Using a laboratory public-good game with voluntary contributions and economies of scale, we construct a situation in which expanding a group's size yields potential efficiency gains, but only if...

We experimentally compare the consequences for group cooperation of two decision mechanisms involving the extension of group membership. We analyze an exogenous decision (random draw) and an endogenous decision (made by a particular group member) mechanism to extend a temporary agent's group...

In repeated public good experiments, reciprocity helps to sustain high levels of cooperation. Can this be achieved by location choices in addition to making contributions? It is more realistic to rely on an intuitive neighborhood model for community members who interact repeatedly. In our...

For decades, experimental economics has been very interested in behavior that could be characterized as practicing solidarity (although the term is rarely used). Solidarity is a key concept in Catholic Social Teaching. This paper builds a bridge between these two endeavors that, thus far, had...