An experimental study of conditional cooperation

Björn Vollan and Elinor Ostrom comment in Cooperation and the Commons on a recent paper Conditional Cooperation and Costly Monitoring Explain Success in Forest Commons Management by Devesh Rustagi, Stefanie Engel and Michael Kosfeld (both articles need subscrption).
Abstract of the paper:
"Recent evidence suggests that prosocial behaviors like conditional cooperation and costly norm enforcement can stabilize large-scale cooperation for commons management. However, field evidence on the extent to which variation in these behaviors among actual commons users accounts for natural commons outcomes is altogether missing. Here, we combine experimental measures of conditional cooperation and survey measures on costly monitoring among 49 forest user groups in Ethiopia with measures of natural forest commons outcomes to show that (i) groups vary in conditional cooperator share, (ii) groups with larger conditional cooperator share are more successful in forest commons management, and (iii) costly monitoring is a key instrument with which conditional cooperators enforce cooperation. Our findings are consistent with models of gene-culture coevolution on human cooperation and provide external validity to laboratory experiments on social dilemmas."

From the comments by Björn Vollan and Elinor Ostrom:
"By establishing this link between the levels of cooperation observed in field labs with local forest conditions, Rustagi et al. have increased the confidence that scholars can have in the external validity of results from previous experiments carried out all over the world, with student and nonstudent subjects. In addition, by adding to findings showing diverse levels of cooperation in social dilemmas, rather than no cooperation, they support the growing acceptance of a behavioral theory of human action (14): Individuals facing dilemmas, who learn from experience and adopt a norm of conditional cooperation, achieve levels of cooperation that increase over time—if a sufficient number of conditional cooperators are present. If a group is composed of a substantial number of free riders, however, cooperation levels fall over time.

One way of interpreting Rustagi et al.'s findings is that learning and norm-adopting individuals are attracted to certain situations, and then are affected by the behavior of other actors facing the same situation (see the figure). Initially, this leads to some degree of cooperation (e.g., acceptance of rules of the forest group, monitoring other users, and helping to maintain their forest). If enough individuals initially cooperate, they slowly obtain benefits from the forest, and levels of cooperation grow. Alternatively, initial cooperation rates can be low, and then can continue to decline over time.

Rustagi et al. identify a number of well-known variables that can influence cooperation, including the size of the forest group, its leadership, and the heterogeneity of the group. Other, broader, variables include village elevation and market access, with villages closer to markets for wood products more likely to invest in cooperative management. Other field studies have found that prior experience in cooperative management increases the likelihood of groups successfully managing a resource."