R&D capital: An engine of growth
论证研发不仅需要熟练的研究工作，还需要专门的机器设备即研发资本，两者共同构成经济增长的双引擎，且在有研发资本时，即使回报递减且人口不增长，也能维持平衡增长，为内生增长与半内生增长之争及长期停滞可能性提供新见解。
Research and development (R&D) requires not only skilled research work, but also dedicated machinery and equipment: R&D capital. In this paper I demonstrate that R&D, producing labor-augmenting ideas, and the accumulation of R&D capital can form a dual engine of economic growth. With R&D capital, balanced growth can be sustained even under decreasing returns and in the absence of population growth. This result contributes to the long-lasting debate on endogenous vs. semi-endogenous R&D-based growth and the likelihood of an upcoming secular stagnation.