During the patent protection period, the patentee has an absolute monopoly on the patent content; After the patent is terminated, anyone can freely and unrestricted use the technology described in the patent.
Therefore, the longer the patent is protected, the greater the benefits the inventors will get from it, and the more they will be encouraged to invest in research and development. At the same time, correspondingly, the longer this monopoly exists, the more additional losses it will cause.
Therefore, the advantage of long patent term is to encourage innovation, and the cost is to encourage monopoly.
With the theory of microeconomics, it can be concluded that when these two contradictory results reach a balance, it is the best patent term.
There are indeed many scholars in the world who have studied this problem. How long is the patent term to encourage innovation and prevent monopoly from causing additional losses? But this problem is also very complicated, because it involves many unknown problems.
Variables and relationships of knowledge. But we can use some simple calculations to estimate. For example, the patent period in the United States is 17 years, which is also 90% efficiency calculated by an American scholar.
In short, intellectual property protection based on the patent system encourages innovation, but it should be considered that patents have three dimensions: length, width and height. Length is the time of patent protection, width is the scope of explaining patent content, and height is the standard of establishing patent novelty. Unfortunately, at present, only the length of patent can be simply quantified. It also led to a large number of enterprises applying for patents in disorder, which led to a decrease in patent quality.