Across two experiments involving over 2,000 participants we vary the potential benefits from cooperation in public good provision. Despite the increased benefits for cooperating, we find no significant change in how much individuals were willing to cooperate. The mechanism behind this behavior seems to lie in individuals' expectations of others’ willingness to cooperate which were also not found to vary with the benefits of cooperating. As participants did not expect others to cooperate more when benefits increased, they were unlikely to increase their own cooperation efforts—even when the benefits of cooperation doubled.
Why is it important?
Our findings highlight a critical gap in our understanding of cooperative behavior in highly-relevant and pervasive single-encounter settings. These results have important implications for how we think about encouraging cooperation in public good provision, especially in urgent, one-time scenarios like disaster relief or emergency volunteering. This research opens new avenues into cooperation in one-time decision settings, in particular how individuals interpret the benefits and respond in such settings, as well as how they expect others to respond; calling for a deeper understanding of the psychological and social factors at play.
Perspectives
This research is the result of many years of preserverence, scientific curiosity, rigor and insightful scholarly exchanges. We couldn’t believe the results ourselves at first, double-checked the data several times, and repeated the study with several populations. The decision to cooperate is characterized by what we call a social dilemma. These are situations where self-interest is in conflict with social interests. With higher benefits from cooperation, however, this conflict is much lower and we would expect to see much higher cooperation rates. We were surprised to see that even when we dramatically increased the benefits from cooperation, people’s cooperation efforts did not rise accordingly. This suggests that real-world cooperation—such as donating to immediate disaster relief—may not always be driven by an assessment of increased benefits. We hope that this research triggers conversations about what we perceive as fundamental knowledge about human cooperation.
Cooperation is a defining trait of human behavior. It plays a crucial role across many areas of society—whether in small, everyday choices or large, complex decisions. Cooperation helps us live and thrive together in groups. In this paper, we focus on extreme scenarios: one-time encounters where individuals are anonymous and unfamiliar with one another. Despite these conditions, we observe significant levels of cooperation, with participants contributing 40-50% of their endowments. People do substantially cooperate even in these environments! Interestingly, this cooperation remains stable to variations in the cost-benefit ratio for group cooperation. With over 2,000 observations from two experiments, eight between-subject treatments, and three distinct subject pools, we can rule out small effect sizes (8-13%)—much smaller than what has been previously reported in studies on repeated interactions. This surprising result highlights the need for a deeper understanding of the fundamental drivers of cooperative behavior.
Cooperative behavior in social dilemma settings is one of the most widely studied areas in experimental economics. The research reported in this study includes over 2000 observations from subjects in a one-shot (single contribution decision) public good setting. This is a very large sample for experiments of this type, the reason being our own surprise with initial results. Thanks in part to colleagues’ comments, we extended the experiment to include both online and a laboratory setting (more common in our research area) as well as across different populations of subjects. Varying the benefits from cooperation in this stark one-decision setting, we did not find a significant across subject response to changes in the benefits from cooperation or in subjects’ expectations of other group members behavior. We did find, however, an important correlation between one’s own cooperative behavior and expectations of others’ behavior. This study suggests the importance of future studies that examine how expectations of others’ behavior are formed and how such beliefs can be altered to promote greater cooperation, in particular in a one-shot decision setting where there is no history between decision makers or expectations of future interactions.
Publication: Increasing benefits in one-time public goods does not promote cooperation,
Proceedings of the National Academy of Sciences, October 2024, Proceedings of the National Academy of Sciences,
https://doi.org/10.1073/pnas.2410326121