| This present study seeks to understand the limits of solidarity in the European Union
(EU) and its relationship to municipal activism (support for irregular migrants). Solidarity is a
foundational legal and normative principle embedded in EU treaties, its practical application has
varied significantly across member states, particularly during and after the 2015 migration crisis.
This study investigates whether solidarity, understood as responsibility and adherence to EU law,
influences local-level policymaking as it relates to municipal activism. Building on existing
literature on multi-level governance and migration policy, this research incorporates solidarity as
an additional explanatory condition alongside established factors such as local autonomy,
political discrepancy, local alliances, economic capacity, and local diversity. Using fuzzy-set
Qualitative Comparative Analysis (fsQCA), the study analyzes 16 major EU cities to identify the
combinations of conditions that lead to municipal activism. The findings reveal that solidarity, in
combination with strong local alliances and high levels of local diversity, is a core condition for
municipal activism. While factors such as political discrepancy, local autonomy, and economic
strength appear in some pathways, they are not consistently decisive. Notably, the absence of
solidarity is strongly associated with the absence of municipal activism, underscoring its critical
role. The results highlight persistent fragmentation in EU migration governance and suggest that
the effectiveness of future reforms will depend on the consistent application of solidarity across
all levels of governance.
Keywords: Solidarity, Municipal Activism, European Union, Migration, Irregular Migrants |