Following the Achmea case of 2018, the Court of Justice of the European Union has progressively developed a far-reaching interpretation of the principle of autonomy of the European legal order that renders difficult the coordination of European law with international investment law.

The RULIERD project aims to reconceptualise the hierarchy of norms of the European legal order to lessen this clash between European law and the international investment legal system, examining reverse discrimination as an understudied and, yet, representative issue of this conflict.

At a theoretical level, RULIERD will be the first research project to explain the connection between the dualistic attitude of the Court of Justice of the EU and reverse discrimination.

At a practical level, it is unclear, in fact, whether reverse discrimination is admissible under article 18 of the Treaty on the Functioning of the EU or under general international law, considering that this legal phenomenon may endanger the principles of equality and fair competition.

RULIERD examines the practical and theoretical aspects of reverse discrimination using an innovative combined methodology that involves the use of law and economics, such as market power theory, which allows defining reverse discrimination and testing whether this legal phenomenon jeopardises the fair functioning of the common market.

The hypothesis is that a neo-monist approach could avoid reverse discrimination.

RULIERD makes both a theoretical and practical contribution: it mitigates the clash between EU law and international investment law and identifies a fairer legal framework for companies operating in the EU market.