United States v. Microsoft is arguably the most important antitrust case of the past decade. It will have major implications for how governments regulate information technologies and the coming Internet explosion. It will also have important consequences for how businesses behave in the marketplace and in the political arena. In this volume, key economists for the government and for the Microsoft Corporation lay out their views on the key issues and then respond to the views presented by the opposing side. The analysis illuminates many of the complex issues involved in assessing the appropriate scope for antitrust intervention in information technology industries.