Platform businesses add value by facilitating interactions between customers who are attracted in part by network externalities. Two-sided platform businesses with low costs of reversing participation status have become more important with the rise of the Internet. This essay is concerned with...

Bolt and Tieman (2008) suggested the prevalence of profit function non-concavity may account for the widespread use of skewed pricing by two-sided platform businesses. In both the Rochet-Tirole (2003) and Armstrong (2006) models, however, skewed pricing may simply reflect substantial differences...