Cross-border functional areas (CBFA): a multi-indicator definition at the European level

Functional cross-border integration in Europe has intensified over recent decades as liberalization processes have increased border permeability. Given its policy relevance, the underlying mechanisms have been widely studied. However, existing approaches to measuring cross-border functionality and identifying cross-border functional areas (CBFAs) remain fragmented and methodologically diverse. The lack of pan-European data at a fine scale has also limited comprehensive quantitative analysis. Building on a scoping review of functional cross-border integration, this article examines how cross-border functionality can be measured. To address gaps in the literature, the study measures cross-border functionality across Europe using municipal-level data and a multi-sectoral set of indicators designed to capture cross-border interactions as accurately as possible. It also presents the first systematic approach to delineating CBFAs across EU and EFTA countries. By providing a robust empirical basis, the study supports targeted border-regional policies through a better understanding of cross-border functional patterns.