Conditional cooperation in case of a global public good – Experimental evidence from climate change mitigation in Beijing

Abstract In this experimental study, we investigate whether when subjects in Beijing, China, have the opportunity to contribute to a global public good, their behavior is conditionally cooperative. For this purpose, participants were offered the opportunity to contribute to climate change mitigation by purchasing permits from the Beijing carbon dioxide (CO 2 ) emissions trading scheme (ETS). The purchased permits were then withdrawn from the ETS. Here, individual behavior is controlled by means of the strategy method. In this study, we observed different types of behavior, including conditionally cooperative behavior. Overall, the probability of contributing to CO 2 emissions reduction is higher if the subjects considering contributing to CO 2 emissions reduction can assume that a two-thirds majority of all the other subjects are also willing to do so, compared to a situation where only up to one-third of all the other participants decide to contribute to this scheme.