The global governance complexity cube: Varieties of institutional complexity in global governance

Recent decades have seen a proliferation in the number, depth and span of interna‐ tional institutions regulating different domains of global politics. Issues like global health, intellectual property rights, climate change and many others that were once governed by relatively distinct rulesets are today regulated by multiple institutions with intersecting mandates and memberships. As a result, the creation, evolution and effectiveness of international institutions are fundamentally shaped by how they relate to other institutions operating within their policy domains. Yet, global governance complexes—that is, clusters of overlapping institutions and actors that govern specific policy issues—differ widely. The number and types of rulesets and actors involved, the degree of overlap between them and the extent to which overlapping rules conflict vary markedly across governance complexes and over time. The same is true for institutional responses to regulatory conflict. The broad trend towards growing institutional complexity in global governance is thus subject to important variation. This special issue examines the nature and consequences of institutional com‐ plexity in global governance, by which we understand the growing number, diversity and interconnectedness of institutions and actors involved in governing global policy issues. Specifically, we explore how variation in the structures of complex govern‐ ance systems may produce variation in governance outcomes. Existing literature on regime complexes (Alter & Meunier, 2009; Helfer, 2004; Raustiala & Victor, 2004) has offered detailed analyses based on the study of specific policy domains like cli‐ mate change (Keohane & Victor, 2011) or intellectual property rights (Helfer, 2004). Such analyses provide an important basis for theorizing the causes and effects of institutional overlap but remain liable to selection bias and limited generalizability