Where the Borders Lie: Mapping Cross-Border Communities in 10 Western European Countries

With the deepening of European integration, Western Europe has witnessed the emergence of highly interconnected cross-border living areas. So far, these areas have received rather limited attention from both quantitative research and public policy. The COVID-19 pandemic dramatically exposed the limitations of the status quo: with travel restrictions imposed at administrative borders and limited cross-border crisis management, the daily life of people in border regions was affected in a disproportionate way. In an effort to better understand the geography of cross-border communities, this paper presents the first large-scale quantitative analysis of cross-border communities in Western Europe. We apply the Louvain community detection algorithm to a transnational, fine-grained dataset gathering commuter flows across 10 Western European countries. This allows us to produce the first comprehensive transnational mapping of communities in these countries and identify five main cross-border living areas. Based on these findings, we put forward policy recommendations aimed at improving the design of mobility censuses and developing new institutional frameworks in cross-border regions.