The purpose of this study is to present the main theoretical contributions in the emergence
of self-enforcing international environmental agreements. We consider models that use as
a policy instrument emission level or abatement efforts. We start our analysis with the
simple static case assuming identical countries. As we relax our assumptions and we
consider asymmetric countries and time dimension larger stable coalition closer to Pareto
optimal state consists an equilibrium. We also investigate policies that assist in the
enhancement of coalition such as transfers trade sanctions and issue linkage. The results
are dubious and the usefulness of these policies depend on the assumptions of each model.
