The New International Tax Diplomacy

International tax avoidance by multinational corporations is now frontpage news. At its core, the issue is simple: the tax regimes of different countries allow multinational corporations to book much of their income in low-tax or no-tax jurisdictions, and many of their expenses in high-tax jurisdictions, thereby significantly reducing their tax liabilities. In a time of public austerity, citizens and legislators around the world have been more focused on the resulting erosion of the corporate income tax base than ever before. In response, in 2012, the G-20—the gathering of the leaders of the world’s twenty largest economies—launched the Base Erosion and Profit Shifting (BEPS) project, the most extensive attempt to change international tax norms since the 1920s. In the course of the BEPS project, the field of international tax has adopted the institutional and procedural architecture for multilateral action used in international financial law. This Article is the first to ask whether that architecture will work in the international tax context. To answer that question, this Article first applies lessons from the international financial law literature to assess international tax agreements that are now being reached through soft-law instruments and procedures comparable to those that characterize international financial law. This initial analysis, which draws from the experience in international financial law, is largely pessimistic. However, this Article then describes how model tax treaty law—although also a form of soft law—is highly effective, and differentiates the political economy of international tax law from that of international financial law. As a result, a key theoretical point emerges: bifurcating analysis of multilateral efforts to change international tax norms into their Model Treaty-based and non-Model Treaty-based components is necessary in order to understand the new regime for international tax governance. At a more practical level, bifurcating the analysis highlights that observers should expect the Model Treaty-based parts of the BEPS project to be implemented, as well as most parts of the project focused on tax transparency. By contrast, sustained international coordination in implementing other dimensions of the project is doubtful. In reaching these conclusions, the Article contributes to the broader international economic governance literature by using a high-profile example from international tax diplomacy to show how underlying legal institutions affect the prospects for implementation of international regulatory agreements