最优专利制度研究

本文构建了一个动态一般均衡模型来研究最优专利长度和最优专利宽度的问题。研究结论表明,最优的专利长度和专利宽度都是有限的。专利长度的增加会通过促进创新来提高社会福利水平,同时,也会导致市场扭曲,从而降低社会福利水平,但随着专利长度的不断增加,前者的效应会小于后者的效应,因此,有限的专利长度是最优的。有效的专利宽度应该一方面使得模仿产品的质量水平不要太低,从而保证模仿产品对专利产品形成潜在的威胁,逼迫专利产品的价格低于垄断价格,减小市场扭曲;另一方面使得模仿产品的质量不要太高,从而保证专利产品能够制定较高的垄断价格,促进创新。

On the Optimal Patent Protect

In this article,a dynamic general equilibrium model is developed to address the issue of optimal patent length and optimal patent breadth. It is showed that optimal patent length and optimal paten breadth are all finite. Increase of patent length induces innovation, so as to increase the social welfare. Meanwhile, it leads to distortion of market also, hence decrease the social welfare. But the latter effect of patent is stronger, when paten length is infinite. So, finite patent length is optimal. Paten breadth is correlated to quality of potential imitation product negatively. Potential high quality imitation product brings decrease of monopoly price of patent product, so as to decrease of distortion of market. On the other hand, potential low quality imitation product leads to high price of paten product, so as to spur the innovation. Therefore, finite patent breadth is optimal.