Fifteen final reports, two European Union anti-tax avoidance directives and two diverted profits tax laws later… This panel will look at the way that countries have implemented both anti-avoidance measures outlined in the base erosion and profit shifting (BEPS) final reports and anti-avoidance measures wholly outside the BEPS framework (and possibly even in conflict with it), considering, inter alia, the anti-avoidance measures under United States tax reform proposals. What makes an anti-avoidance measure work? How do we measure whether such a measure is effective? And how do anti-avoidance measures targeted at a specific problem differ from general anti-avoidance rules already on the books in many jurisdictions?