DERIVATIVE IDEAS AND THE VALUE OF INTANGIBLE ASSETS*
构建一般均衡模型，区分基础创意（引发创造性破坏）和衍生创意（提升现有发明价值），利用专利数据估计衍生创意占70-80%且使知识资本价值翻倍以上。
We build a general equilibrium model where growth is driven by two invention types: fundamental ideas that cause creative destruction, and derivative ideas that enhance the value of existing inventions. The model provides a new mapping from microeconomic, patent data to aggregate total factor productivity growth and the aggregate value of privately owned knowledge. We show how to measure the frequency of derivative ideas and the rate of creative destruction. We estimate that derivative ideas account for 70–80% of all patents and their presence more than doubles the value of knowledge capital relative to what the measured innovation rate might otherwise imply.