Institutional overlap and the survival of intergovernmental organisations

A burgeoning literature emphasises the role of favourable external conditions and institutional design as key drivers of the survival of intergovernmental organisations. This article focuses on institutional overlap as a hitherto overlooked determinant of IGO survival. Studies on institutional complexity posit that overlap - the extent to which organisations perform similar tasks to address similar problems for some common members - may decrease the survivability of IGOs due to rule conflicts, institutional paralysis, and competitive pressures for limited resources. Contrary to this perspective, this article argues that greater overlap increases the likelihood of IGO survival for two reasons. First, similar IGOs will survive as member states use them to pursue forum-shopping strategies. Second, overlap enables IGO secretariats to draw on networks of support from other IGOs, rendering organisations that densely overlap with others more resilient. To test these propositions, the article combines data on institutional overlap in global governance and the survival of the 534 IGOs contained in the Correlates of War IGO dataset. Non-linear regression analysis finds that where organisations overlap more with existing organisations in terms of governance tasks and issue areas, the likelihood of IGO survival increases. Further analysis suggests that this result is driven by the forum-shopping strategies of powerful member states. Given that contemporary world politics is governed by an increasingly dense network of IGOs, these results hold important implications for the study of IGO survivability and the evolution of global governance more broadly.