A key pillar of the Single Market policy, is nowadays the issue of compliance with EU legislation. The main purpose of this work is to examine both theoretically and empirically whether social capital and communitarian legislative enforcement can drive the increase of compliance rate over time. Both national and European level drivers are selected and defined focusing on the impact of different societies and legislations over the institution to institution relationship occurring within the EU. Evidence shows that, with respect to the last decade, compliance rate of the 27 Member States is converging over time while the same is not happening with respect to EU-15. Signs of peer-pressure are detected. Moreover, Member States seem to experience higher degree of “learning-by-doing” effect presumably due to procedures of standardization, whereas public opinion and legislative enforcement display controversial effects.