Two-sided B2B platforms Prepared for Oxford Handbook of Digital Economics, M.Peitz and J. Waldfogel eds.

This chapter provides a roadmap to the burgeoning literature on two-sided markets with a speci\u85c focus on BtoB marketplaces. On-line intermediation involves two-sided network e¤ects between buyers and sellers, and the implications for optimal BtoB platformstari¤s are discussed. The chapter discusses \u85rst the monopoly case, draw-ing attention to the distinction between upfront registration fees and transaction fees. Then the competitive case is discussed, with di¤er-ent degrees of di¤erentiation, the distinction between single-homing and multi-homing, and di¤erent business models. The last section is devoted to non-price issues such as sellers rivalry, tying, the design of the matching process, the ownership structure and sellersinvestment.