Who is responsible for youth policy implementation? This thesis attempts to deepen our understanding of Swedish and Nordic youth policy. Youth policy is cross-sectoral and includes all the decisions and measures affecting the conditions of young people. National youth policy therefore concerns young people's life situations in a number of different areas, such as work, housing, education, health, leisure and influence. The purpose of the study is to increase the knowledge of youth policy work the last century by understanding the impact of youth research concerning adults' role in youth policy implementation.   A mixed method approach has been applied to the study: interviews, documents and youth theory have been analysed. The results show that youth research had a major impact on the Swedish youth policy. It also shows that the state has an important role in the implementation of youth policies. To create a youth policy that meets the democratic mandate, it is necessary to create a systematic approach and guidelines for municipalities. The study has clearly shown that the state's role in the democratic mandate differ significantly over time and that adults' role in the implementation is of great importance. The study draws attention to the perception of adults over time and how adults are increasingly seen as a barrier to young people's democratic schooling, and on what grounds this opinion rests. It is proposed that views on the democratic mandate will be extended from a municipal focus to the state where youth policy have a broader focus that takes account of national welfare goals based on a policy all municipalities has to be involved in.