Patents and Research Investments: Assessing the Empirical Evidence
回顾了Nordhaus模型关于专利期限与研发投资弹性的核心问题，并梳理了近半个世纪以来针对该问题的少量实证证据。
A well-developed theoretical literature--dating back at least to Nordhaus (1969)--has analyzed optimal patent policy design. We re-present the core trade-off of the Nordhaus model and highlight an empirical question which emerges from the Nordhaus framework as a key input into optimal patent policy design: namely, what is the elasticity of R&D investment with respect to the patent term? We then review the--surprisingly small--body of empirical evidence that has been developed on this question over the nearly half century since the publication of Nordhaus's book.