1. Product Compatibility Choice in a Market with Technological Progress;See Michael Katz;Journal of Industrial Economics,1985
2. 1996, available at www.usdoj.gov/atr/speeches. blocking. See Vincenzo Denicol�;Mark Lemley;Journal of Economic Perspectives,1994
3. When innovation is cumulative, basic innovations need forward patent protection, because otherwise future innovators could compete away the original innovators' profits; and because the first innovators should be rewarded for opening the way to the subsequent improvements. The patent system provides forward protection in two ways: first, any patent application must meet certain novelty requirements; second, even patentable improvements may constitute infringement on the original patent, depending on the first-generation patent's leading breadth. See Suzanne Scotchmer;;;International Journal of Industrial Organization,1991