The successive enlargements of 2004 and 2007 have lowered barriers to intra EU mobility. This explains the enormous increase of new member states immigrants to the EU 15 countries – and especially to countries like the UK that have open labour markets. According to this study of the Institute for Public Policy Research, the British economy has benefited from this migration flow through the supply of a young, dynamic, increasingly educated and hard working workforce. Only drawback: because of economic, financial and demographic factors, arrivals from the new member states will start to fall and eventually stagnate. This suggests that, as the other old member states, Belgium will have to diversify its remedies to face challenges like ageing or skilled workforce scarcity: migration alone and open labour markets will not be enough.