Patterns of Declining Infringements in the European Union: A Time-Differencing Qualitative Comparative Analysis

Despite rising Euroscepticism and increasing heterogeneity among member states, infringement cases launched by the European Commission for non-compliance with European Union (EU) law have declined significantly since the introduction of the EU Pilot system in 2008. This downward trend presents a puzzle: while the EU Pilot was designed to facilitate informal pre-infringement dialogue, existing research offers conflicting explanations for compliance patterns. Some studies suggest that Europhile member states drive compliance improvements through catch-up mechanisms, while others argue that Eurosceptic governments use compliance negotiations as bargaining leverage with the Commission. These contradictory findings point to the need for examining complex interactions between member state preferences and institutional capacities. This paper addresses this gap by investigating which combinations of conditions lead to infringement decline across member states. We employ time-differencing Qualitative Comparative Analysis (QCA), a methodological innovation that allows systematic comparison of configurational patterns in cross-sectional and time-series data. Our analysis examines 27 member states across two periods (2003-2011 and 2012-2017), focusing on changes in government attitudes toward the EU, political polarization, institutional structures, and legislative complexity. The findings reveal two distinct sets of pathways to infringement decline that operate through different mechanisms. Europhile member states reduce infringements through catch-up mechanisms, accelerated by positive attitudinal changes and enabled by either veto bicameralism with majoritarian systems or simple legislative procedures with consensual systems. Eurosceptic member states achieve infringement decline through negotiation mechanisms, leveraging domestic political polarization in contexts shaped by their institutional assets. Critically, these mechanisms are not mutually exclusive, as cases such as Germany demonstrate that member states can exhibit characteristics of both pathways simultaneously. The results also suggest that the different negotiation mechanisms between the Nordic countries and other EU countries are produced by their institutional assets. These results demonstrate that compliance dynamics reflect differentiated practices shaped by specific configurations of political will and institutional capacity, advancing our understanding of how diverse member states navigate EU law implementation in an era of increasing heterogeneity.