This paper analyzes individual and group behavior in an experimental commons. Different factors that can help avoid the tragedy of the commons are studied in four experimental settings: separation of a larger commons into smaller commons (two harbors), knowledge/experience available to appropriators, communication within appropriator groups and the possibility of formal and informal sanctioning of group members. Subject populations include undergraduate students as well as professionals working in the Maine lobster and groundfish industries. This design enables a behavioral comparison between students and professionals, as well as a comparison between professionals in these two mutually exclusive fisheries. Results show that group size, communication, geographic separation and subjects' ability to solve the coordination game caused by this separation all contribute to appropriation efficiency on the commons.

We employ a laboratory experiment to investigate the effects of environmental context and termination uncertainty on decisions in a dynamic game with a public bad. Every period the subjects decide on their own production level that generates private revenue and ‘emissions’. Emissions accumulate over time and act as a public bad. We characterize and use as benchmarks the Markov perfect equilibrium and social optimum and find that observed decisions are between the two predictions. We find no significant effect of termination uncertainty on decisions in any except the last few rounds where, in a fixed-end setting, subjects allocate their entire endowment to production. We find a strong effect of environmental context which partially substitutes for experience. The effect of experience is most pronounced in the fixed-end treatment where production allocations and the level of the public bad become lower after the restart.

This paper considers self-enforcing international environmental agreements when countries are asymmetric with respect to emission-related benefits and environmental damage. Considering these asymmetries simultaneously yields large stable coalitions, also without the option of transfers between signatories. However, these large stable coalitions are only possible if they include countries that have relatively high marginal benefits and a relatively low marginal environmental damage. This type of countries hardly contributes to the common good and the gains of cooperation from including this type of countries in the stable coalition are small. This confirms a persistent result in this literature that large stable coalitions usually go hand in hand with low gains of cooperation. Without the option of transfers it is always better to have a small stable coalition with countries that matter than a large stable coalition with countries that do not matter. Only with transfers might a large stable coalition be able to perform better.

This paper analyzes North-South negotiations over climate change abatement. We consider that northern countries have an incentive to negotiate over a transfer to the southern countries in exchange for their abatement efforts rather than reducing their emissions at home. We study the incentives for northern and southern countries to form negotiation-coalitions at each side of the bargaining table and the impact of these negotiation-coalitions on the final outcome. We show that the incentives can be separated into direct efficiency gains, as fixed costs savings, and indirect bargaining power gains. Depending on the relative values of these gains, we determine the equilibrium of the game. We also show that bargaining power gains encourage southern countries to negotiate separately while they encourage northern countries to unite, and that this hinders the formation of the grand coalition.

The Mekong River Basin (MRB) is a trans-boundary river shared by six countries. The governance by the Mekong River Commission (MRC) of the Lower Mekong Basin (LMB) is weak. This study investigates the welfare effects in the year 2030 arising from strengthening the MRC's governance versus joint management of the entire MRB. Without joint management, strengthening the MRC's governance has a huge potential to achieve welfare gains and it requires that the interests of all stakeholders be equally balanced. A bargaining approach shows that the LMB has no incentive to negotiate with China and is better off strengthening the MRC's governance instead. If such strengthening could be realized, further welfare gains of joint management by a wider and stronger MRC, including China, would be very small.