The research presented in this volume was directed by Nina Nyberg Sorensen and is based on case studies from around the world to examine how migration influences development. The studies reveal that it is seldom the simple act of migrating, but rather the conditions under which migration takes place that determine the developmental impact of migration. Rather than dwelling on normative discussions about whether migration should contribute to development, whether remittances should be put to more developmental uses, whether return should be promoted or whether development cooperation should engage in collaborative efforts with migrant and refugee diasporas, the chapters focus on the questions policymakers and practitioners should consider when making background analyses for such decisions.