Smile curve of technological learning: a case study of nuclear power reactor technology in China
研究中国核电反应堆技术中“干中学”与“进口中学”两种学习机制在不同发展阶段如何协同演化，发现两者相对重要性呈微笑曲线，为技术追赶政策提供新视角。
Abstract Despite extensive research highlighting the importance of technological learning in fostering development, there is still limited understanding of how different learning mechanisms co-evolve across various stages of technological advancement. To address the gap, we develop a theoretical framework elucidating the co-evolution of two learning mechanisms—learning by doing and learning by importing, which are defined as learning from domestic or foreign technological knowledge sources, respectively. Using a combination of interview-based exploratory and quantitative analysis, this paper conducts an embedded case study focusing on nuclear power reactor technology and finds that learning by doing lays the groundwork for learning by importing through enhancing absorptive capacity at every stage of technological development (“duplicative imitation—creative imitation—innovation”). More importantly, we derive the smile curve of technological learning: the evolution of the relative importance of learning by doing and learning by importing, along with that of the two components of learning by importing (intangible and tangible), both exhibit a smile curve. Our study contributes to technological learning and stage theories, presenting novel insights into policy measures for technological catch-up, particularly through the co-evolution of two learning mechanisms and the dynamic interplay between sectoral and national innovation systems.