I explore possible impacts of reciprocal preferences on participation in international environmental agreements. Reciprocal countries condition their willingness to abate on others' abatement. No participation is always stable. A full or majority coalition can be stable, provided that reciprocity is sufficiently strong and widespread. In addition, a stable minority coalition can exist, even with weak reciprocity preferences. This latter coalition is weakly larger than the maximum stable coalition with standard preferences, but is characterized by mutually negative sentiments.
International Environmental Agreements Reciprocity Coalitions