Expectations, Network Effects and Platform Pricing

by Andrei Hagiu & Hanna Hałaburda

Overview — In markets with network effects, the value that users gain from platforms depends on the number of other users of the same type who join the same platform (direct network effects) or the number of users of a different type that join (cross-group network effects). Examples include social networks like Facebook or Google+, payment systems like PayPal or Visa, videogame systems like PlayStation 3 and Xbox 360, smartphone platforms like Apple's iPhone or Google's Android, etc. Users typically rely on the media, market reports, or word of mouth to form expectations about the total number of other users that join a given platform. However, most of the time these users are unable to calculate the effect of platforms' prices on adoption by other users. In other words, they do not take price into account when forming expectations. To analyze platform profits, Andrei Hagiu and Hanna Hałaburda model different degrees of user sophistication in forming price expectations in markets with network effects. They show that firms have different preferences regarding the average sophistication of their user base depending on market structure. Key concepts include:

  • Firms with market power always prefer to face more sophisticated users, while firms competing for share in a market of fixed size always prefer to face more unsophisticated users.
  • Firms' preferences create different incentives to educate users about the effects of prices under different market structures.
  • Specifying how expectations are formed is key to accurately estimating the strength of network effects and the impact of prices on demand.

Author Abstract

In markets with network effects, users must form expectations about the total number of users who join a given platform. In this paper, we distinguish two ways in which rational expectations can be formed, which correspond to two different types of users-sophisticated and unsophisticated. Only sophisticated users adjust their expectations in response to platforms' price changes. We study the effect of the fraction of sophisticated users on platform profits. A monopoly platform's profits are always increasing in the fraction of sophisticated users. The profits of competing platforms in a market of fixed size are decreasing in the fraction of sophisticated users. When market expansion is introduced, the fraction of sophisticated users that maximizes competing platforms' profits may be positive and is strictly lower than 1. We also investigate the possibility of platforms investing in "educating" unsophisticated users. In a competitive environment, such education is a public good among platforms and therefore the equilibrium level is lower than the one that would maximize joint industry profits.

Paper Information