Traditionally, environmental policy in most countries is based on command and control and - to a lesser extent - on the more modern economic instruments. Today, there is a strong need for complementing this traditional policy with a set of approaches that rely on communication and informal influence to stimulate voluntary and cooperative action. The comprehensive and analytical description of these approaches and the related instruments presented in this book extend environmental policy thinking by in-depth treatment of tools for communication and diffusion, collaborative agreements, as well as service and infrastructure instruments. The different types of approaches and instruments are described in detail from an actor-oriented perspective. Special emphasis is put on new approaches based on principles of social and behavioural psychology. To date, these have barely been discussed in relation to conventional instruments. Several empirical studies carried out in Switzerland illuminate selected aspects and combinations of traditional and innovative instruments using methods of economy, psychology, political sciences, and jurisprudence. These studies touch, in particular, on energy policy, waste water treatment, transport, and household behaviour. The present work originates in a broad inter- and transdisciplinary cooperation among academic scientists, researchers in private consultancy firms, and beneficiaries of the research, i.e. decision-makers in politics, public administration, companies, and non-governmental organisations. In a special chapter, the methods and procedures applied to developing integrated research results as well as to organising cooperation and communication with non-academic project partners are described and evaluated. The book addresses scholars from different disciplines, mainly experts in political, economic, social, and behavioural sciences as well as educated lay persons interested in modern sustainability policy.