The Design of Enforcement: Collective Action and the Enforcement of International Law

Abstract

International organizations (IOs) play a vital role in enforcing international law. Many treaties are built on transnational enforcement, in which private actors challenge and litigate possible legal violations. Others feature international enforcement, in which only states can challenge possible violations. Some feature centralized enforcement, in which an IO has its own authority to challenge possible violations. I argue that collective action problems drive decisions about whether to enforce international law, and hence affect the optimal design of enforcement regimes. When cooperation generates concentrated benefits --- such as compensation for the expropriation of foreign investment --- transnational enforcement can work well because the cost and benefit of enforcement are both fully internalized by the litigant. However, when cooperation generates diffuse benefits --- like a cleaner environment --- individuals and even governments have incentive to free-ride on enforcement, avoiding the cost of litigation in the hopes that another actor will step up. In such circumstances, supranational enforcement is necessary to uphold international law. Finally, hybrid regimes, which contain multiple forms of enforcement, are most needed when an IO has members that vary in their ability to enforce, or regulates issue areas that vary in their diffuseness. I assess my argument by examining litigation in the European Court of Justice, and provide inductive evidence that the European Union is more likely to enforce EU laws that generate diffuse benefits, while private actors and governments are more likely to enforce EU laws that generate concentrated benefits.