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...

This book provides an updated overview of the recent progress in the theoretical study of third-degree price discrimination. It is a marketing tactic and is said to be present if the unit price is different across different groups of buyers. Its welfare evaluation is often difficult because it...

Two-sided platform firms serve distinct customer groups that are connected through interdependent demand, and include major businesses such as the media industry, banking, and the software industry. A well known textbook result in one-sided markets is that a government may increase a...

This paper analyzes the impact of network externalities on R&D competition between an incumbent and a potential entrant. The analysis shows that the incumbent always invests more than the entrant in the development of higher quality network goods. However, the incumbent exhibits a too low level...