"Eliezer S. Yudkowsky" wrote:
> Tim Bates, <email@example.com>, writes
> > How do you defend patent expiry if it is a right? To me, if patents are
> > justified, they should last forever. Just like when you buy some land, it
> > is not yours for 50 years. It is yours, period. The fact neither of us
> > thinks that patents should last in perpetuity suggests that patents are
> > property but are rather a state tool arrived at by trading off the
> > interests of one power group against another. The losers are you, me, and
> > innovative companies.
> Limited patent rights maximize innovation. After 20 years, it is
> assumed that your patent would have been obvious in any case - that it
> would have been invented even without a patent system or a patent office
> or any other motive to make a research investment.
The purpose of a time span is to allow the inventor and his or her financial backers to recoup a respectable return on investment on the capital needed to bring the new technology to market. Its is merely a method of protecting private investment in research and development, so the government doesn't have to fund it all. Giving a patent a time span to earn ROI puts a tangible value on an invention, whereas when it is not protected, a patent is only worth something in the time between it intially comes to market and when the competitor can backward engineer it to reproduce it and bring it to market. When the time span to obsolescence decreases to a point where it is shorter than the time required to reverse engineer something and bring it to market, then patents will cease to have much value except as a means of retarding the growth of competitors, and protecting the value of the new generation of product from heavy discounting in the value of the previous obsolete generation.