Better Together? How International Organizations Combat Complexity Through Cooperation

International organizations (IOs) operate in increasingly dense institutional networks. This means that IOs rarely act in isolation; instead, their decisions are shaped by the activities performed by other IOs in their issue area. However, existing literature focuses primarily on how individual IOs can solve cooperation problems in a vacuum. How and when can IOs broadly, and U.S.-led liberal IOs in particular, effectively pursue their mandates against the backdrop of institutional crowding? In a three-paper dissertation, I probe the evolution of multilateral cooperation networks and how they structure policymaking in liberal IOs. To explore these dynamics, I construct an extensive, hand-coded dataset of cooperation between organizations in the development and emergency lending issue spaces 1945-2018. This coding draws on the contents of thousands of organizational policy papers, program documents, and press releases. I then leverage quantitative methods, text analysis, and network modeling to analyze these data. I supplement the empirical results with semi-structured interviews and experimental research designs. While existing work suggests that IOs must make concessions to member