The material basis of modern technologies. A case study on rare metals

Scientific progress in many technologies exploits new materials. The unique properties of a wide range of Rare Metals (RMs) make them key inputs to achieve the functionality of emerging technologies. The speed of technological progress can therefore be influenced by the availability of necessary RM materials. This paper discusses these relations and provides a first exploratory empirical analysis of the link between critical raw materials and frontier technological innovation. By text mining 5,146,615 USPTO patents during the period 1976-2015, we explore the dependence of new inventions of 13 key RMs, finding that the latter play an increasingly important role as the material basis of modern technologies: in the four decades observed, more than 1/10 patents rely on at least one RM. This dependence increases significantly over time and is particularly high for emerging technologies such as semiconductors, nanotechnology, and green energy. Further, we adopt a panel of 5644 technology subgroup-RM pairs to explore the impact of variations in RM supply. The results show that, controlling for science & technology push and demand-pull factors, innovation in RM-based technologies is positively associated with its supply conditions, contributing to the understanding of the shifts of critical materials' use in frontier technologies.