Why do we need evidence based youth policies? International in scope, this book presents a systematic and interdisciplinary reflection on what has been termed the "magic triangle", i.e., the relationship between youth policies, youth research and practical youth work, based on the necessity of organising knowledge exchange between different actors in the youth field. On this basis, researchers from across the globe analyse and discuss youth policy development, the theories that underlie youth policy, as well as the models and impact of youth policy in different societies. They respond by: - Analysing the impact of economic, social and cultural change on young people in different world regions, locations and social contexts; - Presenting and explaining theories of youth; - Discussing strategies for the development and implementation of youth policies in different world regions; - Evaluating the impact of current youth policies at regional, national and international levels; - Analysing and discussing applied models of cross sectional policy and practice in the youth sector; - Discussing contributions of youth research to the development of evidence based youth policies in areas such as values, employment, participation, citizenship, migration, social exclusion and vulnerability.