The proliferation of multilateral development banks

Since 1945 the number of multilateral development banks (MDBs) has increased at a linear rate, with approximately one new MDB created every three years. The proliferation of MDBs has resulted in an inefficient duplication of international institutions with overlapping functions. Further, this trend contradicts our existing understanding of why states create countervailing international organizations. This article proposes a novel, two-step theoretical model of institutional change and creation in an attempt to explain this empirical puzzle. Utilizing the complementarities of rational-choice and historical institutionalism, the model demonstrates that the rational actions of states in the past can lead to seemingly irrational institutional change in the future. This process results in the repetitive creation of countervailing MDBs designed to solve the same functional problems. To evaluate the model’s hypotheses, three case studies are undertaken, employing archival material, internal documents, and 48 interviews conducted by the author in London, Washington, D.C. and Manila, Philippines. The empirical results are of direct interest to policy-makers currently negotiating the structure of new MDBs in Asia and Latin America.