Microsoft Plays Hardball: The Use of Exclusionary Pricing and Technical Incompatibility to Maintain Monopoly Power in Markets for Operating System Software

Abstract:     
This article examines Microsoft's licensing practices for its MS-DOS and Microsoft Windows operating system software. Our main focus is on Microsoft's use of CPU (central processing unit, or per-processor) licenses, under which an original equipment manufacturer (OEM) of personal computers pays a royalty for each machine it ships instead of for each unit of MS-DOS installed. We also examine Microsoft's practice of requiring in these licenses a minimum number of personal computers (PCs) on which MS-DOS can be installed, Microsoft's tying of Microsoft Windows and technical support information to the sale of MS-DOS, and Microsoft's attempts to induce technical incompatibility between MS-DOS and its main competitor, DR-DOS. Finally, we turn to the proposed consent decree between Microsoft and the Department of Justice.

JEL Classifications: K21, L41, L42

Accepted Paper Series