Method & caveats
Capture = share of country i’s imports of material m that comes from m’s dominant global exporter. China mode shows the share from China specifically. Lock-in = the country’s own import-source HHI and top-source share (≥70% from one source flags a single-source dependency). The per-country score = capture × √(import HHI): high when you buy heavily from the global chokepoint AND have few alternatives.
Caveats. This is import-based: a country that refines for itself simply imports less, so a low exposure can mean self-sufficiency, not resilience (China’s own row is small because it feeds itself). It captures refined-goods dependence via trade, not stockpiles, long-term contracts, or domestic mines. Shared HS codes (gallium/germanium 811292) are a basket. Top 40 importers by critical-material import value are shown; the open dataset covers all. Built by build_leverage.py on CEPII BACI. See also Break the chokepoint and the reallocation stress test.