政府研发的回报：来自美国拨款冲击的证据

中文摘要

基于对五个主要联邦机构战后所有重大研发拨款变动的叙述性分类，我们发现，非国防研发拨款的增加会在长期内提升创新活动的多项衡量指标，并提高企业部门生产率。我们运用 Lewis 和 Mertens (2024) 的 SP-IV 方法，对非国防政府研发资本的生产函数弹性进行结构估计，得到战后时期 140% 至 210% 的隐含回报。这些估计表明，政府资助的研发占二战以来企业部门全要素生产率增长的五分之一，并意味着非国防研发存在相当大的资金不足。

Abstract

Based on a narrative classification of all significant postwar changes in R&D appropriations for five major federal agencies, we find that an increase in nondefense R&D appropriations leads to increases in various measures of innovative activity and higher business-sector productivity in the long run. We structurally estimate the production function elasticity of nondefense government R&D capital using the SP-IV methodology of Lewis and Mertens (2024) and obtain implied returns of 140 to 210 percent over the postwar period. The estimates indicate that government-funded R&D accounts for one-fifth of business-sector TFP growth since WWII and imply substantial under-funding of nondefense R&D.