For many products, platforms enable sellers to transact with buyers. We show that the competitive conditions among sellers shape the market structure in platform industries. If product market competition is tough, sellers avoid competitors by joining different platforms. This allows platforms to...

In many markets, user benefits depend on participation and usage decisions of other users giving rise to network effects. Intermediaries manage these network effects and thus act as platforms that bring users together. This paper reviews key findings from the literature on network effects and...

Central features of today’s electronic communications markets are complementarities between the different layers of the value chain, substitutability between some applications, network effects in the provision of content and services, two-sided business models that partly involve indirect...