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...

Interrelated global crises - climate change, pandemics, loss of ecosystem services and biodiversity - pose risks that demand collective solutions. Uncertainty about others' behavior, coupled with the dependence on some to take collective efforts to mitigate risks for all (e.g. conservation of...