An Antitrust Rule for Software Integration

J. Gregory Sidak


What is the proper legal standard for product integration involving software? Because software is subject to low marginal costs, network effects, and rapid technological innovation, the Supreme Court’s existing antitrust rules on tying arrangements, which evolved from industries not possessing such characteristics, are inappropriate.

In this Article, I ask why firms integrate software products. Next, I review the Supreme Court’s tying decisions in Jefferson Parish and Eastman Kodak. I propose an approach to judging the lawfulness of product integration in technologically dynamic markets that supplements the Supreme Court’s current standard with four additional steps in cases of tying of computer software. Thereafter, I examine the D.C. Circuit’s approach to software integration, which arose from that court’s 1998 interpretation, in Microsoft II, of an antitrust consent decree between the U.S. Department of Justice and Microsoft Corporation. I argue that the D.C. Circuit’s rule has general applicability and should be recognized as the appropriate standard for software integration under antitrust law.

I show how my approach imparts greater clarity to the D.C. Circuit’s rule. I examine the competing product integration rule proposed in 2000 by Professor Lawrence Lessig as amicus curiae in the government’s subsequent antitrust case against Microsoft, concerning the integration of Internet Explorer and Windows 98. My approach enables Professor Lessig’s analysis to be reconciled with the D.C. Circuit’s rule, but Professor Lessig’s rule, on its own, would contain serious shortcomings. Thereafter, I evaluate Judge Thomas Penfield Jackson’s April 2000 findings of law on the integration of Internet Explorer and Windows 98. I conclude that Judge Jackson’s approach, in contrast to the D.C. Circuit’s rule as refined by my approach, would harm consumers in the technologically dynamic market for computer software.

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