The MFN Principle at Peril in Investment Treaties - with Particular References to Ansung Housing and Beijing Urban Construction

Purpose - This paper investigates the theories and practices of Most-Favored-Nation (MFN) clauses. The MFN clause became a controversial issue during the past two decades, especially in the context of investment arbitration. This paper aims to clarify a reasonable way to apply MFN clauses. It in particular focuses on the territoriality requirements and the scope of investment activity which are common features included in most of investment treaties. Design/methodology - This paper analyses two investment arbitration cases, Ansung Housing and Beijing Urban Construction. Through the case study, this paper reveals limitations of the currently dominant views on the operation of MFN clauses. It then tries to reconstruct the system of MFN application within the relevant arbitration principles. Findings - Tribunals of recent investment arbitration as represented in the two cases above employed strict literal interpretation of the treaty provisions, especially of the phrase “in its territory”. This paper finds a more functional interpretation is appropriate and consistent with theories of public international law and developments of global economy. Originality/value - Existing studies either stuck to literal interpretation or suggested more flexible interpretation of the phrase “in its territory” without full explanation. This paper tries to fill the gap in the existing discussion by analyzing legal foundations and theoretical structure for an effective interpretation of MFN clauses.