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.