We discuss the case of a monopolist of a base good in the presence of complementary goods provided either by it or by other firms. We assess and calibrate the extent of the influence on the profits from the base good that is created by the existence of complementary goods, i.e., the extent of...

This paper proposes a theoretical framework for studying the invention of new products when demand is uncertain. In this framework, under general conditions, the threat of ex post entry by a competitor can deter invention ex ante. Asymmetric market power in the ex post market exacerbates the...

The fundamental contribution of the paper is to contest the view that greater market contestability has non-negative effects on market performance. In a model where employees pose a threat of potential entry, we demonstrate that a reduction in barriers to entry causes no fall in industry price...

I study Cournot competition under incomplete information about demand while assuming that market price must be non-negative for all demand realizations. Although this assumption is very natural, it has only rarely been made in the earlier literature. Yet it has important economic consequences:...

Our one-page reply to Whinston and Siegal's forthcoming AER article correcting and elaborating our 1991 AER article.

Models of durable goods with network externalities that set instantaneously have emphasized that a monopolist selling those goods has too high an incentive to introduce new vintages of the durable good, to make previous vintages (already bought by consumers) obsolete. This is referred to as...

This paper analyzes optimal pricing for information goods under incomplete information, when both unlimited-usage (fixed-fee) pricing and usage-based pricing are feasible, and administering usage-based pricing may involve transaction costs. It is shown that offering fixed- fee pricing in...

A durable-goods monopolist may use quality degradation as a commitment not to lower price in the future. The introduction of damaged goods expedites low-valuation consumers’ future demands, and helps the firm to mitigate the Coasian time-consistency problem. In such a case, damaged goods are...

A number of products that display positive network effects are used in variable quantities by heterogeneous customers. Examples include corporate operating systems, infrastructure software, web services and networking equipment. In many of these contexts, the magnitude of network effects are...

The Microsoft antitrust case focused public attention on the role of antitrust enforcement in preserving the forces of innovation in high-technology markets. Traditionally, regulators focused on whether companies artificially hiked prices or reduced output. Now, they're increasingly likely to...