Econ Papers Daily / 期刊论文
累积创新增长模型中专利工具的最优组合
Optimal Combination of Patent Instruments in a Cumulative-Innovation Growth Model
摘要
We develop a tractable general equilibrium model of cumulative innovation and growth to study the optimal combinations of three patent instruments: a patentability requirement to protect against future incremental innovation, a patent breadth to protect against current imitation, and the patent length governing the duration of its validity. New ideas strictly build upon frontier technologies, with the size of productivity improvements drawn from a stochastic distribution. The model features positive knowledge spillovers, and we discuss when this leads to under-investment in R&D in the market equilibrium relative to the social planner’s benchmark. We characterize analytically how each patent instrument affects research incentives, and further establish that the patentability requirement and patent breadth in the welfare-maximizing combination are each set at a strictly lower level than in the R&D-maximizing combination. Calibrating the model to aggregate data, the welfare-maximizing combination of instruments features a large patent breadth, a long patent duration, but a modest patentability requirement. The quantitative analysis points to sizeable welfare gains from these patent policies, while highlighting the importance of having multiple patent instruments.
中文摘要
我们构建了一个易于处理的累积创新与增长一般均衡模型，旨在研究三种专利工具的最优组合：保护未来增量创新的可专利性要求、保护当前模仿的专利宽度，以及决定其有效期限的专利长度。新思想严格建立在尖端技术之上，生产力改进的规模从随机分布中抽取。模型包含正向知识溢出效应，我们讨论了在何种情况下，这会导致市场均衡中的研发投资相对于社会规划者基准而言不足。我们分析性地刻画了每种专利工具如何影响研究激励，并进一步确立，在福利最大化组合中，可专利性要求和专利宽度均严格低于研发最大化组合中的水平。将模型校准至总体数据后，福利最大化的工具组合表现为较大的专利宽度、较长的专利期限，但适度的可专利性要求。定量分析指出这些专利政策能带来显著的福利收益，同时强调了拥有多种专利工具的重要性。