As of today, only 2,8 % of all EU citizens live in a EU country that is not their native country. And only 0,1% of European workers move between countries annually for work reasons. The corresponding figure for the US is 3%. What does this mean for the Single Market? For businesses and the creation of jobs? For getting out of the economic crisis? For the future of European unity and prosperity? And what- if anything- should be done about it at the EU-level