This article introduces a special forum devoted to the evolution of international regime complexes in three parts. First, it develops a novel distinction between adaptive and maladaptive evolution and maps diverse patterns of change in well-known and emerging international regime complexes. Second, it theorizes a variety of exogenous and endogenous sources of change that impact the configuration and effects of regime complexes. Here it draws on theories of regime complexity, along with theories of power transition, institutions, and delegation, to explain variations in evolutionary patterns. Finally, the paper summarizes eleven original contributions that make up the special forum and lays the groundwork for further theorizing about the conditions under which regime complexes adapt in ways that enhance or undermine international cooperation. We find, among other things, that the prevalence of endogenous sources of change is positively associated with adaptation of regime complexes, and invite further investigation of this relationship.
Over the last 30 years, the accountability system of the World Bank Group institutions has evolved into a complex ecosystem, encompassing the Inspection Panel, the Compliance Advisor Ombudsman (CAO), and the Grievance Redress Service (GRS). The creation of the World Bank Accountability Mechanism (WBAM) in 2020, which encompassed the existing Inspection Panel and Dispute Resolution Service, added another layer of complexity to the Bank’s accountability system. This study examines the evolution of the World Bank’s accountability mechanisms by combining principal–agent theory with scholarship on regime complexity. It contends that the emergence of multiple, sometimes overlapping accountability bodies within the World Bank Group arose from competitive interactions and rivalry between the Executive Board (the principals) and World Bank management (the agent). Over time, the proliferation of accountability bodies has led to adaptive differentiation, with the creation of the CAO and GRS, increasing efficiency and introducing a division of labor between the Inspection Panel and the CAO. Conversely, as part of the principal–agent contest, the establishment of the WBAM introduced maladaptive differentiation and fragmentation into the Bank’s accountability system. By tracing the development of these multiple accountability mechanisms, the study helps us to better understand the evolution of the Bank’s complex multilayered accountability ecosystem.
