Justiça fiscal internacional e tributação de lucros de grupos multinacionais

Multinational enterprises (MNE) are the main contemporary player in international trade and investment. However, taxing their profits is becoming increasingly challenging due to their transactional nature and the structuring of the international tax system, based on a separate legal entity approach. This approach provides leeway for tax planning opportunities exploited by MNE’s unified management and the implementation of variables of substitutive behavior motivated by tax purposes. As a consequence, the aptly designated phenomena of base erosion and profit shifting occurs and MNE are frequently able to unfairly reduce their tax burden. In the present dissertation, we seek to establish guiding principles for evaluating the current international tax system. Subsequently, we contrast positive law with the previously elaborated principles of fairness in international taxation, departing from the analysis of International Law, Treaty Law and Portuguese Law. Thus, we identify and try to demonstrate that the transfer pricing regime is at the core of base erosion and profit shifting. We then elaborate on how recent developments in international tax are not fit to overcome the limitations of the transfer pricing regime for its anti-abuse purposes and hamper the fair sharing of tax bases between States. Departing from the methodological shortcomings of the transfer pricing regime, we then turn to the analysis of the treatment of MNE by Corporate Law, concluding for the need to revamp international tax rules to ensure fairness in the taxation of MNE. We propose progressive integration of formulary apportionment methods in the rules for group taxation and profit splitting between affiliates by using a formula based on three fators: “assets”, “labor” and “receipts”. Our proposal would blend in with the current transfer pricing rules and the separate entity approach for group taxation purposes. Finally, we conclude that our proposal would improve the fairness of international and national tax systems.