He's assuming that the 20-year monopoly discourages innovation. Perhaps a better phrasing is: "In granting a 20-year monopoly, patents can have good and bad e

He's assuming that the 20-year monopoly discourages innovation. Perhaps a better phrasing is: "In granting a 20-year monopoly, patents can have good and bad effects; they can encourage invention by appealing to inventors who desire a limited-time monopoly, but they can discourage invention by scaring away inventors who don't want to run afoul of patents already held by others. In the field of software, which already had a high rate of invention without the encouragement of patents, the benefits of patents are marginal and are likely outweighed by their drawbacks." Of course, the challenge is to quantify the argument and back it up with facts.