With the increasing worldwide problems of migration, research into its causes and effects become every more urgent. This volume takes stock of recent advancements that social science research in both Europe and the United States has made to understanding central aspects of international migration. The focus is on conceptual, methodological, and theoretical contributions that have emerged out of empirical research with regard to state policies and interests toward migration, dual citizenship, incorporation, transnational ties, entrepreneurship, illegal migration, intergenerational incorporation, and religion. No other publication brings the scholarship together in a similarly comprehensive manner, showing how the different approaches on each continent complement and speak to one another, thus contributing to the internationalization of migration studies.