This article explores the heterogeneous and uneven EU response to the COVID-19 pandemic across policy fields and examines how integration theories can contribute to explaining the presence (or absence) of new integration steps and their varying nature. To analyse European activities in three policy fields, namely fiscal policy, centralised European vaccine procurement, and border politics, we develop a ‘Domain of Application’ approach (DOA). Instead of testing integration theories against each other, DOA allows bridging different theoretical traditions by making use of their complementary explanatory power to derive better explanations of complex empirical issues. We find that Liberal Intergovernmentalism and Neofunctionalism offer complementary explanations for several empirical puzzles, which together provide a more compelling picture of the effects of the pandemic on European integration. In addition, DOA advances our understanding of the scopes of both theories.
- Border politics
- European integration
- domain of application approach
- vaccine procurement