The main focus of this study is an assessment of the macro-economic impact on both host and home countries of the increased labour mobility that has resulted from the two recent EU enlargements. We first look at the macro-economic impact of the total population flows from the EU-8 and EU-2 to the EU-15 economies between 2004 and 2009. The aggregate population flows to the EU-15 are adjusted to reflect the age structure and education level of the mobile population. We also consider the impact of remittances. We then attempt to quantify the share of population movements that have occurred since 2004 and 2007 that can be attributed to the enlargement process itself, and the share that is likely to have occurred even in the absence of EU expansion. We finally look at the impact that transitional restrictions on the free mobility of labour have had on the distribution of EU-8 and EU-2 citizens across the EU-15 countries.