The European Union (EU) may promote reforms to policies and institutions through at least two distinct mechanisms. First, accession to the EU requires countries to undertake reforms. Second, the EU common market may promote Tiebout jurisdictional competition. We empirically evaluate these two mechanisms using an unbalanced panel of up to 45 European countries during 1970–2010. We find that relationships between EU accession/membership and measures of policies/institutions are often statistically insignificant. Furthermore, when the estimated effects are statistically significant they are generally modest.