I discuss the impact of tying, bundling, and loyalty/requirement rebates on consumer surplus in the affected markets. I show that the Chicago School Theory of a single monopoly surplus that justifies tying, bundling, and loyalty/requirement rebates on the basis of efficiency typically fails....

We discuss strategic ways that sellers can use tying and bundling with requirement conditions to extract consumer surplus. We analyze different types of tying and bundling creating (i) intra-product price discrimination; (ii) intra-consumer price discrimination; and (iii) inter-product price...

We examine the intersection of patents and antitrust where a patent holder uses the monopoly power it possesses in the market for a patented product to exclude competitors in an adjacent market and attempt to monopolize or monopolize the adjacent market. The present scheme for awarding patents...

This paper asks how much the strength of network effects depends on the stability and structure of the underlying social network. I answer this using extensive micro-data on all potential adopters of a firm's internal video-messaging system and their subsequent video-messaging. This firm's New...

We discuss and compare the remedies in the two cases antitrust cases of the European Union (EU) against Microsoft. The first EU case alleged (i) that Microsoft illegally bundled the Windows Media Player (WMP) with Windows; and (ii) that Microsoft did not provide adequate documentation that would...

We analyse a newspaper market where two editors first choose the political position of their newspaper, then set cover prices and advertising tariffs. We build on the work of Gabszewicz, Laussel and Sonnac (2001, 2002), whose model we take as the stage game of an infinitely repeated game, and...

We study horizontal mergers on two-sided markets between horizontally differentiated platforms. We provide a theoretical analysis of the merger's price effect based on the amount of cost savings it generates, the behavior of outsider platforms, and the size of cross-group network effects. We...

The Microsoft cases in the United States and in Europe have been influential in determining the contours of the substantive liability standards for dominant firms in US antitrust law and in EC Competition law. The competition law remedies that were adopted, following the finding of liability,...

This paper investigates the price war in the UK quality newspaper industry in the 1990s. We build a model of the newspaper market which encompasses demand for differentiated products on both, the readers and advertisers side of the market, and profit maximization by four competing oligopolistic...

Online communities provide a social sphere for people to share information and knowledge. While information sharing is becoming a ubiquitous online phenomenon, how to ensure information quality or induce quality content, however, remains a challenge due to the anonymity of commentators. This...