Despite their crucial contribution to regional integration, trade networks have rarely—if ever—been mapped, formally described, and modelled. In such a dynamic business environment as West Africa, traders rely on their social networks to carry out their business, but the precise patterns of such networks remain largely unknown. This recent paper « Business, Brokers, and Borders » aims to fill this gap by showing how the social and spatial organization of trade networks in West Africa can be formally modelled. The authors built on a fast-growing field of research known as Social Network Analysis (SNA) to map how 136 large traders dealing with building materials, cereals, textiles, and used clothes are connected across borders. The study focuses on five markets located in Nigeria, Niger, and Benin—three countries among which there are intense import and export flows of agricultural and manufacturing products.