Uncertainty and the Dynamics of R&D
发现不确定性在经济衰退时大幅上升，会降低研发对商业条件变化的反应速度（“谨慎效应”），使研发更持久，并影响技术政策效果。
Uncertainty varies strongly over time, rising by 50% to 100% in recessions and by up to 200% after major economic and political shocks. This paper shows that higher uncertainty reduces the responsiveness of R&D to changes in business conditions - a “caution-effect” - making it more persistent over time. Thus, uncertainty will play a critical role in shaping the dynamics of R&D through the business cycle, and its response to technology policy. I also show that if firms are increasing their level of R&D then the effect of uncertainty will be negative, while if firms are reducing R&D then the effect of uncertainty will be positive.