This book explores Public Procurement novelties and challenges in an interdisciplinary way. The process whereby the public sector awards contracts to companies for the supply of works, goods or services is a powerful instrument to ensure the achievement of new public goals as well as an efficient use of public funds. This book brings together the papers that have been presented during the "First Symposium on Public Procurement", a conference held in Rome last summer and to be repeated again yearly. As Public Procurement touches on many fields (law, economics, political science, engineering) the editors have used an interdisciplinary approach to discuss four main topics of interest which represent the four different parts in which this book is divided: Competitive dialogue and contractual design fostering innovation and need analysis, Separation of selection and award criteria, including exclusion of reputation indicators like references to experience, performance and CV's from award criteria, Retendering a contract for breach of procurement rules or changes to contract (contract execution), Set-asides for small and medium firms, as in the USA system with the Small Business Act that reserves shares of tenders to SMEs only.