In the globalized economy, labor migration has become of central importance. A key issue in the analysis of immigration is how the migrants fare in the economy in which they migrate, and how they assimilate towards the behavior of the natives. Using data from the United States, Canada, many European countries, Australia and New Zealand, the chapters study the developments of earnings, employment, unemployment, self-employment, occupational choices and educational attainment after migration. The book also investigates the role of language in labor market integration and examines the situation of illegal, legalized and unwilling migrants. Policy effects are also studied: Among those are the effects of selection criteria of labor market success and the effects immigrants have on the public sector budget of the receiving country. Hence, the book provides a broad picture of the performance of migrants.