Source-based taxation and the arm’s length standard have been foundational elements of the international tax system for many decades.  With the advent of the highly digitalized platform firm, the OECD and many other stakeholders assert that these principles have been rendered obsolete.  In their stead, these stakeholders have proposed an alternative hybrid international tax system.  Under this proposed hybrid system, the long-standing profit allocation rules would be applied in the first instance to determine the preliminary attribution of in-scope multinational firms’...