Joining the club: European Union accession and the quality of national football teams

This article investigates how European Union (EU) accession affects the quality of national football teams. Using Bulgaria, Romania, and Croatia as late-accession cases, we exploit the staggered timing of their entry to estimate the causal impact of joining the European Union through a difference-in-differences framework applied to monthly ELO ratings (1997–2022). Results show that EU accession is associated with a sudden and persistent decline in national team performance, amounting to about 50 ELO points at entry and nearly 80 after 3 years. This deterioration coincides with a marked increase in the share of players employed abroad, suggesting that integration, while expanding individual opportunities, weakens collective quality. EU enlargement thus provides a useful institutional setting in which to examine how major regulatory changes can generate transitional costs in domains where coordination and identity matter, highlighting the dual nature of integration: efficiency gains at the individual level versus short-term losses in collective performance.