Hal R. Varian is the Class of 1944 Professor at the School of Information Management and Systems, the Haas School of Business, and the Department of Economics at the University of California, Berkeley. Joseph Farrell is Professor of Economics in the Department of Economics at the University of California, Berkeley. He has served as Deputy Assistant Attorney General and Chief Economist at the Anti-Trust Division, US Department of Justice, 2000–1. Carl Shapiro is the Transamerica Professor of Business Strategy at the Haas School of Business at the University of California at Berkeley. He also is Director of the Institute of Business and Economic Research, and Professor of Economics in the Economics Department at the University of California, Berkeley.

• List of figures; The Raffaele Mattioli lectures; Part I. Competition and Market Power: 1. Introduction; 2. Technology and market structure; 3. Intellectual property; 4. The Internet boom; 5. Differentiation of products and prices; 6. Switching costs and lock-in; 7. Supply-side economies of scale; 8. Demand-side economies of scale; 9. Standards; 10. Systems effects; 11. Computer mediated transactions; 12. Summary; Part II. Intellectual Property, Competition and Information Technology: 13. Introduction; 14. Patents, trade secrets and copyrights; 15. Differentiation of products and prices; 16. Switching costs and lock-in; 17. Standards and patents; 18. Do we need to reform the patent system?; 19. Summary and conclusions; Bibliography; Index of names; Index of subjects.