Product-scope sensitivity and cascade vulnerability in global rare-earth trade networks

Critical-mineral trade-network assessments are sensitive to product classification and to how simultaneous disruptions are modelled. Using import-reported UN Comtrade data for 2014–2023, this paper examines product-scope sensitivity and cascade vulnerability in rare-earth-related midstream and permanent-magnet trade networks. An external audit shows that Australian HS253090 trade closely tracks official lithium-concentrate exports, so this code is excluded from rare-earth network inference. The primary comparison uses HS284690 rare-earth compounds and HS850511 metal permanent magnets, with broader baskets retained as sensitivity checks. Under the central stress-test specification, a China-origin disruption generates larger conditional node-failure fractions in HS850511 than in HS284690 under baseline procurement (48.6% versus 20.8%) and procurement stress (86.3% versus 52.8%). These percentages are conditional stress-test outputs rather than estimates of realized disruption. The downstream–midstream ordering holds across all 16 combinations in the procurement-stress parameter grid. Matched-scale destination rewiring shows that cascade exposure can change substantially even when China’s total export value, export degree, and shipment-size distribution are fixed. Exporter concentration alone is therefore insufficient to characterize supply-chain vulnerability; product definition and bilateral dependence also matter.