Mechanisms of informal governance: evidence from the IEA

How does informal governance occur in international organisations? While the existing literature suggests that power asymmetries matter a great deal for explaining the uncodified rules and procedures that often develop within international organisations, we argue that power asymmetries alone cannot explain informal governance. Consequently, we develop two specific mechanisms through which informal governance occurs. First, we suggest that regime complexity can act as a source of incentives and opportunities for informal governance. In the face of regime complexity, informal governance offers an attractive way of keeping states bound to the organisation and of managing complex interactions with adjacent regimes. Second, we propose that the coincidence of frozen formal structures and changing causal beliefs allows informal governance to emerge. Problems of great causal complexity are sometimes subject to swings in beliefs about cause–effect relationships, demanding new policy approaches. When such swings occur, and if it is costly to adapt an organisation’s formal rules, states and institutions often simply create unwritten, informal practices as a way to render the institution dynamic. The plausibility of our conjectures is illustrated with evidence drawn from the International Energy Agency.