Firms are often organized into groups. Group membership has been shown empirically to have positive effects, in the form of increased prosocial behavior toward in-group members. This includes an enhanced willingness to engage in altruistic punishment of inefficient defection. Our paper provides...

We investigate how group boundaries, and the economic environment surrounding groups, affect altruistic cooperation and punishment behavior. Our study uses experiments conducted with 525 officers in the Swiss Army, and exploits random assignment to platoons. We find that, without competition...

We test the effectiveness of self-help peer groups as a commitment device for precautionary savings, through two randomized field experiments among 2,687 microentrepreneurs in Chile. The first experiment finds that self-help peer groups are a powerful tool to increase savings (the number of...