What this replaces, and why one page is better
The atlas used to carry this as several separate rankings — a value index, a tonnes index, a governance-weighted index, a recycling-adjusted index — each one an argument about which weighting is “right.” They were all correct and all incomplete, because the honest finding is that the weighting is a choice, not a fact. Collapsing them into one dial makes that visible and testable: a robust dependency (gallium, rare-earth magnets, tungsten) sits near the top however you set it; a fragile one moves. For the external reality check — does any of this recover an independent expert list? — see the IEA cross-check. For the deeper “is concentration even measured right” question, the per-commodity status map. This index takes concentration as given and asks only: once you have it, what do you multiply it by?
Ingredients (each material’s three HHIs, its top producer’s governance score, its recycling rate and substitutability) are assembled by build_risk_index.py from the atlas’s own risk_index.json. Governance from World Bank WGI; recycling/substitutability from USGS. Adjustments are transparent multipliers, shown below, not a black box.