Advancing the analysis of resilience of global phosphate flows
This paper introduces a novel method for estimating material flows, with a focus on tracing phosphate flows from mining countries to those using phosphate in agricultural production. Our approach integrates data on phosphate rock extraction, fertilizer use, and international trade of phosphate-related products. A key advantage of this method is that it does not require detailed data on material concentrations, as these are indirectly estimated within the model. We demonstrate that our model can reconstruct country-level phosphate flow matrices with a high degree of accuracy, thereby enhancing traditional material flow analyses. This method bridges the gap between conventional material flow analysis and the economic analysis of resilience of national supply chains, and it is applicable not only to phosphorus but also to other resource flows. We show how the estimated flows can support country-specific assessments of supply security: while global phosphate flows appear moderately concentrated, country-level analyses reveal significant disparities in import dependencies and, in some cases, substantially higher supplier concentration.