Income evaluation method: convert the expected future expected income of the evaluated patent into present value, so as to determine the price of the evaluated patent. It's really hard to say how big this future income is. The evaluation institution's judgment on the future patent benefits is too subjective, the patent benefits are closely related to the object of implementation, and there is no basic analysis of the patent value, which leads to many difficulties in the practice of patent evaluation.
Market comparison evaluation method: evaluate the price of the target patent by comparing the prices of similar patents in the market. This method is also difficult to achieve. First, it is difficult to define what a similar patent is, not to say that it can be evaluated as a similar patent just because the technical field is close; Second, the price of similar patents does not necessarily represent the price of the patents involved.
Manufacturing cost evaluation method: investigate the cost paid by the company to generate the target patent, and estimate the patent price, including purchase cost, maintenance cost and labor input cost. If the management of scientific research funds in enterprises is standardized, this method can really estimate the manufacturing cost of patents more accurately, but it will ignore the possible future value of patents, so it is one-sided.
Copy cost evaluation method: evaluate by estimating the redevelopment cost of patent application. It is necessary to consider the cost of developing the same technology under new inflation or price conditions. This method ignores organizational capital and does not consider the possible value of patent transformation.