Our understanding of innovation processes has dramatically changed over the past decades. Interactive models of innovation, differing significantly from the linear approach, now emphasize both the importance of networking activities both within and across firms, and the centrality of knowledge spillovers which lie at the root of the formation of networks. The study of knowledge spillovers has become a major focus of research on innovative networks in recent years. Part of this research tradition can be traced back to the early work of Alfred Marshall on external economies through which 'industrial districts' - as he termed them - were integrated. This book brings together a collection of articles and book chapters which present an overview and synthesis of current knowledge in the Economics of Innovation. It both reviews what is known and accepted as the best thinking on selected topics in the field and provides research findings that offer valuable insights into the nature and process of innovation, network formation and network activities, knowledge generation and spillovers from a regional perspective. By presenting the articles and book chapters as a whole, this collection is a novel combination. It is being published simultaneously with Spatial Analysis and GeoComputation: Selected Essays. Innovation, Networks and Knowledge Spillovers is essentially a multi-product undertaking, in the sense that the various contributions are largely multi-authored publications. All these co-authors deserve the full credit for this volume, as they have been the scientific source of the research contributions included in the present volume.