type="main" xml:id="ecca12074-abs-0001" <p>Experience from climate policy suggests that full cooperation among all countries is not a likely outcome. In this paper we therefore consider the case where only members of a subgroup of countries cooperate by reciprocally matching their public good...</p>

A theoretical model of emission reductions is specified that accounts for voluntary and nonvoluntary behavior regarding the adherence to the Helsinki and Sofia Protocols, which mandated emission reductions for sulphur and nitrogen oxides, respectively. From this model, the authors derive an...