GAARs and Treaties. From the Guiding Principle to the Principal Purpose Test. What Have We Gained from BEPS Action 6?

The issue of General Anti-Avoidance Rules and treaties is a legal problem as old as double tax conventions themselves. However, the BEPS Project, materialized in 15 Actions and particularly in the Final Report of BEPS Actions 6, involves a radical change in the very physiognomy of the problem. Apart from the inclusion of a Limitation-on-benefits rule in the OECD Model, the most groundbreaking innovation arising from BEPS Action 6 would be the incorporation, also to the Model, of a GAAR (the Principal Purpose Test). This article will examine the pros and cons of the PPT vis á vis the old paradigm. It also seeks to analyze some new problems originating from the very existence of the PPT