This invaluable book provides a comprehensive overview of twenty years of research on the economics of innovation and patent policies. Edited by Bruno van Pottelsberghe de la Potterie, the papers in this volume witness twenty years of advanced empirical research — triggered by intensive collaboration and inspired by his own professional experience at the OECD, METI and the European Patent Office. The Editor's publications in these fields have greatly contributed to better understand how innovation can be stimulated, how it can be measured, through which channels it contributes to growth, with a particular emphasis on the role of patent systems. In the introductory chapter, the Editor provides an overview of each subfield of investigation, by explaining the genesis of the research projects and adding some personal history. The book first displays major empirical findings on the effectiveness of science and technology policies in stimulating R&D, on how these policies affect the contribution of R&D to economic growth, and how to measure international R&D spillovers and what are their most effective channels. The policies that aim at stimulating innovation include R&D subsidies, public R&D, and R&D tax credits. The chapters that follow present foundational work on patent count methodologies aiming at improving innovation metrics, as well as creative contributions on patent valuation models. The book then presents pioneering contributions on the design of patent systems, including a thorough work on the role of fees, far-reaching analyses on quality, and critical contributions on the governance of patent systems in general and the European patent system in particular.