An empirical approach to determine specific weights of driving factors for the price of commodities—A contribution to the measurement of the economic scarcity of minerals and metals

Abstract

In recent years, commodity markets show a large amount of volatility and substantial price jumps, indicating an increasing economic scarcity in many cases. As this scarcity makes commodity procurement a critical issue for national economies, industry sectors and manufacturing companies, a number of criticality indices have been presented and utilized in science as well as in practice. These indices are mostly based on an aggregation of different key figures, both qualitative and quantitative. However, the weighting of the different factors is in most cases arbitrary or based on rough estimates.While this may be inevitable in some areas, we believe that an empirically based aggregation is desirable and to some degree attainable. While the broad concept of criticality is certainly hard to operationalize from a quantitative point of view, the economic scarcity is not only one important factor of criticality, but can be measured to some extent by the material's market price.Therefore, in this paper we show that each single raw material comes with a fundamentally different set of relevant factors for its economic scarcity. We determine those by performing an extended regression analysis on the market price (dependent variable) of 42 (out of about 60 industrially relevant) chemical elements, based on a broad range of empirical datasets, covering 11 driving factors (independent variables) and a 26 year time span. Our analysis determines specific weights for the factors of scarcity of each raw material and takes into account the material's individual characteristics.We expect these results to be valuable for refining the aggregation of criticality assessments, as scarcity is at least one aspect of criticality and many influence factors we analyzed are currently utilized in criticality studies. However, our results are contrary to a number of well-known studies on criticality of raw materials, which assign generic weights to the different driving factors of different commodities and therefrom derive a criticality index. Instead, our results suggest a specific model for every single material when assessing availability risks in criticality evaluation methods. Therefore we hope that our results provide an additional empirical perspective regarding the weighting of factors for criticality based on the economic scarcity of minerals and metals.