20 years of EU Membership: What Explains the Accession Bonus?

2024 marked the 20th anniversary of the EU accession of ten economies. Their experience was characterised by rapid growth in per capita incomes. Of the 23 percentage points of average convergence observed between the EU-10 and Germany between 2003 and 2023, 6 percentage points are shared with other emerging markets with similar characteristics, while the remaining 17 percentage points can be thought of as an ‘EU accession bonus’, facilitated by rapid growth in exports relative to GDP as they became deeply integrated into supply chains. Looking at the impact of EU accession in earlier waves, 20 years after joining, we also estimate a large ‘EU accession bonus’ for Spain and Portugal (which joined in 1986). Austria, Finland and Sweden (which joined in 1995) outperformed their synthetic controls only in the longer term and when comparators exclude Iceland, Liechtenstein, Norway and Switzerland – non-EU economies with access to the internal market.