So I had an idea the other day for a patent reform: property tax on patents.<p>As long as a company wants to keep the monopoly rights over a patented invention, they are taxed a percentage of the patent's market value each year. They can choose either to pay that tax or sell the patent to someone else.<p>The government would offer to buy any patent for its market value, using tax revenue gathered from other patents, in doing so putting the invention into the public domain.<p>This would discourage companies from building large 'defensive' patent portfolios, since they'd be expensive to maintain. It works for the 'lone inventor' scenario too, since the market value of a new, untried invention would be low.<p>Once a patent's value is proven by developing the patent, its value will rise. At some point, the benefit derived from the patent's monopoly rights will no longer be worth the cost, and the rational thing to do is sell the invention.