From network structure to network evolution in cross-border cooperation: a longitudinal analysis of a Polish-German cross-border region

Border regions have long been analysed as microcosms of broader European integration processes, where integration becomes concrete through cross-border interlinkages. The European Commission supports such interlinkages through Interreg. Yet, network analytical studies of cross-border cooperation have not explicitly analysed network evolution. This paper proposes a dynamic framework and asks how cooperative relationships evolve and what shapes their emergence and durability. Using temporal exponential random graph models and a new dataset of small Interreg projects in one Polish-German cross-border region over two Interreg periods, the paper shows that past embeddedness – through community membership and actor centrality – increases the likelihood that new ties emerge. By contrast, persistence is less consistently associated with these mechanisms and appears more sensitive to programme rhythms and organisational capacity. These findings show that integration across borders unfolds through relational dynamics over time, and they demonstrate the value of longitudinal network analysis for European integration research.