The Changing Face of Enforcement: Analysing the EU’s Emergent Compliance Promotion Architecture

Since the 1990s, implementation, compliance and enforcement have been key themes in EU studies (Overhaart & Mastenbroek, 2026; Zhelyazkova, 2024). With the advent of alternative compliance promotion instruments (Mastenbroek et al., 2026; Smith, 2016), the research agenda has diversified, with sub-literatures on three types of instruments. The ‘vertical’ instruments are better regulation (Dunlop & Radaelli, 2022), strategic legislative design (Blom-Hansen, 2005; Kelemen, 2011), assistance (Börzel & Buzogány, 2019), monitoring (Zwaan & Schoenefeld, 2024), dialogue/EU Pilot (Cheruvu & Fjelstuhl, 2021), EU agencies (Blauberger & Heindlmaier, 2024; Versluis & Tarr, 2013). The key ‘horizontal’ instruments are administrative cooperation (Hartlapp & Heidbreder, 2018), European Administrative Networks (Martinsen et al., 2022; Thatcher & Coen, 2008), peer review (Sabel & Zeitlin, 2008), and coercive coordination (Butler, 2017; Li & Newman, 2022). The key ‘domestic’ instruments are information provision (Börzel, 2009; Newig & Koontz, 2014), stakeholder participation (Börzel (2009), decentralized enforcement (Hofmann, 2018), and the role of domestic agencies (Coen & Thatcher, 2008; Maggetti & Gilardi, 2011). In recent work (Martinsen et al., 2022; Mastenbroek et al., 2026a, 2026b; Treib et al., 2022), we have used these literatures to map the EU’s variegated compliance promotion structure and review the existing literature on their functioning and effectiveness. Yet, this picture is rather blurry and underexposed in places, due to a variant evidence base. This workshop aims to close this gap and shed further light on the development, functioning and effectiveness of EU compliance promotion. It also aims to stimulate engagement and accumulation between these sub-literatures.

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1: What are the roles of the Commission and other EU institutions as compliance promotion architects?
2: How and by whom is the Commission in its role as EU compliance promotion architect being held accountable?
3: What are the differences in EU compliance promotion instruments between policy areas and how can these be explained?
4: What do we know about the functioning and effectiveness of these novel EU compliance promotion instruments?
5: How do these instruments interact, both within and between the vertical, horizontal and domestic arenas?

1: We invite qualitative and quantitative research papers on the following themes:
2: 1. The role of the Commission and other EU institutions as compliance promotion architects;
3: 2. Oversight on the role of the Commission as guardian of the treaties / compliance promotion architect;
4: 3. Differences in the compliance promotion architecture between policy areas;
5: 4. Functioning and effectiveness of EU compliance promotion instruments;
6: 5. Theoretical explanations and mechanisms (e.g. managerialism, constructivism, rationalism);
7: 6. Interaction between compliance promotion instruments across and between arenas of application.