Consider a situation in which countries anticipate an international environmental agreement (IEA) to be in effect sometime in the future. What is the impact of the future IEA on current emissions after its announcement? We show that the answer to this question is ambiguous. We examine four types...

The provision of public goods regularly embodies interrelated spheres of influence on multiple scales. This article examines the nature of human behavior in a multilevel social dilemma game with positive provision externalities to local and global scales. We report experimental results showing...

This paper proposes a simple mechanism aimed to establish positive contributions to public goods in the absence of powerful institutions to sanction free-riders. The idea of the mechanism is to require players to commit to the public good by paying a deposit prior to the contribution stage. If...