This book offers an innovative perspective on the political science debate on implementation problems. Previously unconsidered problem-solving potentials of the action-relevant knowledge of actors on the implementation level are brought into focus. The central question is whether the shape of political control instruments can structure the way in which the implementing actors bring their knowledge into the political process and thus contribute to a more effective achievement of political goals. The book offers a theoretical examination of this question, a concept for the analysis of empirical case studies and two case studies from the field of "New Environmental Policy Instruments" in the European Union. With the European emissions trading system and the strategic environmental assessment, two instruments are examined that give the addressees pre-structured scope for action.