DTU-REMS-II follows up on the work begun by DTU-REMS-I, which is in the process of mapping the key enforcement challenges in multi-level regulatory systems (e.g., multiple enforcers, differing standards of protection, the impact of a digitalized society). DTU-REMS-II will move beyond this pioneering work, by taking an overarching look at the important, complex interactions across international, European, and domestic levels within multi-level regulatory systems and will make a normative analysis thereof. DTU-REMS-II will be structured around two interlinked research questions: (1) what are the structural gaps and failures in enforcing multi-level regulatory norms against public and private actors operating across jurisdictions; and (2) which solutions respect the core constitutional principles of democracy, fundamental rights’ protection, and the rule of law. On a methodological level, these core constitutional principles will form the evaluative criteria for a comparative institutional analysis of a wide range of enforcement mechanisms. These two questions will guide research clustered around four research axes: (1) courts, alternative dispute resolution mechanisms, and quasi-judicial bodies in multi-level regulatory systems; (2) the public-private divide and its challenges for enforcement; (3) norms and normative instruments at the cross-roads of legal systems (enforceability and availability of legal remedies); and (4) complementarity between ex ante compliance mechanisms and ex post enforcement. Research on these themes will take both an intra-disciplinary (gathering different legal disciplines) and inter-disciplinary approach (legal and economic research).DTU-REMS-II’s comprehensive research, by filling an overlooked niche, will yield information highly relevant to Luxembourg, as well as innovative ideas accompanied by substantial outreach and broad publication. DTU-REMS-II will advance, in a ground-breaking manner, the scholarly knowledge needed to sustain informed policy choices, both by assessing the effectiveness of multi-level enforcement systems expected to respect the core constitutional principles and by comparing and contrasting alternative multi-level enforcement mechanisms (or combinations thereof) against this normative background.