Why have some international organizations gained in authority, while others have seen their authority decline? Recent scholarship has begun to analyze variation in IO authority across organizations. However, we lack a clear understanding of institutional change over time. To explain why member states are willing to delegate more authority to some IOs but revoke authority from others, we draw on a new database on the authority of 36 representatively sampled IOs over the period 1919-2015. Our data contains detailed information on the right and the capacity of these IOs to set the agenda, to adjudicate disputes, to monitor rule compliance, and to impose sanctions against member states. Focusing on interest similarity and the power distribution within IOs, we take special care to accurately model institutional change and estimate a series of error-correction models (ECM) for our panel data. Beyond predicting changes in IO authority over time, the ECM allows us to model endogenous institutional dynamics and to address concerns about simultaneity that often plague institutional analysis. Our approach yields novel insights into how state interests and power interact to produce institutional change.
