The dynamics of the transfer and renewal of patents
利用美国专利转让与续展的新数据，发现转让比例因技术领域和专利人类型而异，且转让概率受专利年龄、引用次数、通用性及是否曾被交易等因素影响。
This article explores new data on the transfer and renewal of U.S. patents and inter-prets this new evidence using a model of patent transfers and renewal. We find that the proportion of transferred patents is large and differs across technology fields and especially types of patentees. We also find that the probability of a patent being traded depends on a number of factors—the age of the patent, the number of citations received by a given age, the patent generality, and whether the patent has been previously traded or not—. These findings are consistent with the predictions of a model of patent transfers and renewals. ∗I am very grateful to Thomas Holmes and Sam Kortum for their advice and patience. I would also