Overlap and interplay between international organisations: theories and approaches.

This article aims to make a contribution to existing building blocks for a theory on the organisational interplay of international organisations. Thereby, the article first provides for a review of existing approaches on regime interaction which have contributed much to our understanding of organisational interplay by promoting concepts such as overlap and nestedness. Second, the article advances the idea of rational interplay based on resource dependencies. It is argued that interplay presupposes mutual resource dependencies to emerge and that resource exchange is governed by the principle of equitable exchange. Third, the consequences of organisational interplay are examined and an explanation is sought for the tendency of IOs to either develop niche capabilities or imitate other institutions. In this context the importance of institutional variance is highlighted. [ABSTRACT FROM AUTHOR]