In today's globalised world, innovation plays a major role. For states, the generation of new knowledge through innovations impacts economic development and the standard of living. For companies, innovation is crucial to achieving a competitive advantage. Specifically, the concept of Open Innovation has been advocated to improve innovative performance. This book explores the economics of Open Innovation in 'Systems of Innovation' and related opportunities with a focus on the three main actors: firms, academia and the state. Based on quantitative analyses, insights for practitioners in innovation management and public management, as well as future research opportunities, are derived. For example: For corporate innovation managers, this book finds a 'compensation effect' of openness: Open Innovation can be used by firms located in rather difficult regional environments to compensate a firm's locational disadvantage compared to peers with rich regional endowments. Opening up the innovation processes reaches its maximum value when the firm's learning environment is most difficult. Taking a public innovation management perspective, this book analyzes the "Aufbruch Bayern" platform as one of the first endeavors in Germany to employ open innovation methods for collaborative idea generation in the public sector. Public innovation managers willing to maximize the creative potential for public innovation need to recognize such new participation opportunities. Methods like collaborative online innovation platforms allow public managers two-way communication with citizens and to reach additional 'contributors'. In order to lead collaborative participation programs to success, public servants need to become innovation promoters.