A cartel forms when competitors conspire to limit competition through coordinated actions. Most cartels are composed exclusively of firms that would otherwise be in competition, but in a hub-and-spoke cartel, those competitors (“spokes”) conspire with the assistance of an upstream supplier or a downstream buyer (“hub”). This book provides the first comprehensive economic and legal analysis of hub-and-spoke cartels, explaining their formation and how they operate to create and sustain a collusive environment. Sixteen detailed case studies, including cases brought against toy manufacturer Hasbro and the Apple ebook case, illustrate the economic framework and legal strategies discussed. The authors identify three types of hub-and-spoke cartels: when an upstream firm facilitates downstream firms to coordinate on higher prices; when a downstream intermediary facilitates upstream suppliers to coordinate on higher prices; and when a downstream firm facilitates upstream suppliers to exclude a downstream rival. They devote a chapter to each type, discussing the formation, coordination, enforcement, efficacy, and prosecution of these cartels, and consider general lessons that can be drawn from the case studies. Finally, they present strategies for prosecuting hub-and-spoke collusion. The book is written to be accessible to both economists and lawyers, and is intended for both scholars and practitioners.