No fences, good neighbors: measuring and explaining integration in European cross-border regions

EU cross-border regions are defined as living laboratories of European integration by scholars and EU institutions. Nonetheless, on the research agenda of EU studies, the study of integration in cross-border regions is not central. Moreover, the dearth of explanatory research has hampered a comprehensive understanding of the determinants of cross-border integration. This article fills these gaps conceptually, theoretically, and empirically. It introduces a new conceptualization anchored in classic integration theories and a new measurement of integration in all 2014-2020 Interreg A programmes. Furthermore, by drawing on a post-functionalist framework and based on multiple linear regression analysis, the study shows that identity pressures, particularly linguistic proximity and a pro-European sentiment, and contextual effects, notably regional authority, are significantly positively correlated with cross-border integration, all other things being equal. The paper thus not only reveals to what extent cross-border regions are integrated but also which explanatory factors are associated with cross-border integration.