The eastward enlargement of the EU in 2004 and 2007 is the only example in modern times of the introduction of free movement of labor between countries with such widely differing income levels. The economic consequences of the ensuing migration have been a hot topic of political discussion in several of the old EU countries since then. Of these countries, Sweden was the only one that did not introduce temporary restrictions on the access of new EU citizens to the labor market and welfare system in either 2004 or 2007. Sweden is therefore uniquely placed to explore the economic consequences already now. Previous research has reported on migrants' employment, income, benefit receipt and short-term impact on the public sector. However, these early results are static averages of more experienced migrants and a significant proportion of newly arrived inexperienced migrants. They are therefore likely to be misleading for the longer-term situation. This project uses register data where migrants are followed for up to ten years to study income assimilation and selective re-migration and thus the long-term economic consequences of migration. The following five sub-questions are answered: 1. How long do migrants stay? 2. do the economically more or less successful stay longer, i.e. is there positive or negative selection in return migration? 3. how does income and benefit receipt evolve over time for those who stay? 4. What is the impact of boom/bust cycles on 1-3? 5. What are the likely long-term consequences for Sweden's public sector?