The Southern Africa Migration Project (SAPM) launches its new series on migration and development. Migration has been an integral aspect of the labour markets across much of Africa for at least the last century, cutting across class and skill boundaries. It represents an important livelihood strategy for poor households, but is also characteristic of the better off, including many African elites. Understanding is slowly emerging of the potentially positive role that migration can play in reducing poverty and 'mobilising' the African diaspora in development. This first title in this series provides an overview of the complex political, economic and human development issues at stake around the migration phenomenon in the twenty-first century. It gives valuable factual and statistical data to inform debates on this contentious political topic. This publication is the product of collaboration between the Southern African Migration Project and the Centre for Globalization, Poverty and Migration at Sussex University. Subsequent editions are planned on HIV/AIDS, health, the brain-drain, and food security in Africa.