Disaggregation of Financial Instruments in International Tax Law

Disaggregation is the technique of decomposing a facts pattern into components and their separate legal subsumption. As a pre-step to prepare a legal case, it is an all too practical problem and therefore seems to be rather neglected in the high art of jurisprudence. This contrasts with the great importance of the substance over form doctrine in legal practice, being a universal and timeless issue in all fields of law dealing with economic subjects and in all jurisdictions. At the example of financial instruments as the ‘burning lens’ of tax law and the OECD Model Tax Convention (OECDMTC) as the ‘tax system for tax systems’, this article contributes a discussion base for a methodologically supported concept to disaggregation. Inspired by U.S. federal tax policy, finance theory and International Financial Reporting Standards (IFRS), the author takes the liberty of a progressive and unconventional approach. Its centrepiece is an iterative process of identifying, decomposing, and eliminating economic risk types utilizing findings from portfolio theory and option pricing. Disaggregation, bifurcation, fragmentation, unbundling, disassembly, decomposition, OECD Model Tax Convention, financial instrument, substance over form, look-through.