Author: Christoph Hauert
In view of dwindling global resources, increased pressures on social welfare states, and the threat of climate change, the sustainable management of public goods presents formidable challenges to human societies. In two behavioral experiments on public goods interactions and the closely related collective risk dilemma, individuals are asked to contribute funds to a common pool, which benefits everyone and hence generates a social dilemma where rational individuals attempt to free-ride on benefits generated by others—to the detriment of all. Public goods experiments show that revealing the identities of individuals who contributed least (shame), or contributed most (honor), both result in a significant increase of cooperation. This reflects practices that, for example, mandate restaurants to display health inspection results, or maintain public lists of the top tax delinquents. In the context of climate change, cooperation is significantly harder because the problem is global, participation is mandatory, and resources as well as risks are highly unevenly distributed. Possibly worst of all, the benefits of not contributing are immediate, whereas the rewards for successfully mitigating climate change are delayed by decades. Future rewards are discounted due to the risk that rewards may not get realized or the beneficiary may not live to enjoy them. In collective risk experiments participants were tasked to raise a target amount to avert “dangerous climate change.” Any leftover funds were theirs to keep (i.e., there were immediate benefits for shirking) and if the group achieved the target, additional benefits were paid out either the next day, seven weeks later, or, invested into planting oak trees. Comparing inter- and intra-generational discounting reveals a sobering trend: the longer the delay, the fewer groups reach the target. Our experiments confirm that negotiations to mitigate climate change are unlikely to succeed if individual countries’ short-term gains can arise only from defection.
Christoph Hauert is an associate professor in the Mathematics Department of the University of British Columbia, Canada. Previously he has worked in the University’s Zoology Department and collaborated with Martin Nowak in the Program for Evolutionary Dynamics at Harvard University; among other positions. His primary research interest lies in the evolution of cooperation and the role of population structures.