Voting rules crucially structure decision-making processes in international organizations. Designing voting rules is not just a matter of choosing the functionally optimal solution – there are also fundamental normative questions at stake: Who is entitled to participate in decision-making? Should states be treated equally or differentially (e.g. based on their size or their contribution to the organization)? When debating IO voting rules, international actors therefore also negotiate their conceptions of what is fair and just. Dissatisfied members often pick the voting rules of an organization to express their frustration and to demand adjustments in the institutional architecture. The paper will discuss the role of conflicting notions of justice in debates about voting rules in international organizations. It will demonstrate the necessity for member states to use justice claims when they defend their position, the difficulties that arise when competing notions of what is just and fair are put forward, and the ways in which actors deal with these difficulties. To do so, it introduces a large-n data set containing information about voting rules and their negotiation in international organizations worldwide and uses a nested-analysis design to select interesting cases from it for in-depth study. It expands on one of these cases to demonstrate the importance of justice concerns in conflicts about voting rules: the challenge to IMF voting rules posed by the demands of rising powers.
