An interactive multi-criteria approach to admit new members in international environmental agreements

Whether and how new members can join international fisheries agreements, which are in charge of managing the global commons, is a complex issue and remains unresolved in the scholarly literature. This paper presents a simple, participatory and fair procedure, which utilizes the concepts of minimum rights and the nondiscrimination principle to propose “compromise” share of fishing rights to a new member. In the specific case of tuna management in the Atlantic regulated by the International Commission for the Conservation of Atlantic Tunas, our proposal was tested using a number of fairness indices, namely the Gini Coefficient, the Duclos, Esteban and Ray Index and the Decile Ratio. Then the Reference Point Method, an interactive multi-criteria framework, was used to aggregate the fairness indices in order to balance the allocation principles, namely the equal sharing and the minimum rights. The compromise solution gives priority to the nondiscrimination principle as captured by the ‘equal share’ rationale.