• group-levelRuthenium: reserves reported only at the PGM group level - USGS MCS publishes reserves for the platinum-group metals as a single aggregate (world total >76,000,000 kg PGM in 2025; South Africa 63,000,000 kg), with no per-metal split. The empty reserves table reflects the source's reporting grain, not missing coverage.
• no dataNo commodity-decomposed recycling data - No USGS MCS Fig13 scrap rows. EU WEEE / battery EOL flows (Phase 6.1.1) are country-keyed only - see country profiles.
• datedMaterial-flow analysis is historical - All 11 material-flow records date to 2010 or earlier (Yale STAF era). They describe the anthropogenic cycle of that period, not today's system.
• datedEnvironmental footprint is dated - Cradle-to-gate intensity rows carry a 2008 inventory vintage (Nuss & Eckelman-era LCA). Current-process footprints are not yet in scope.
• datedExport-restriction inventory ends 2020 - The OECD industrial-raw-materials inventory (vendored snapshot) reports HS-line measures only through 2020; restrictions enacted since are not reflected in the measure table.
• narrowConsumption geography is single-economy (World) - Reported consumption covers one economy only - the world usage split must be read from trade flows, not from a consumption table.

The eight-stage lens, the observed-vs-estimated membrane, stage-honest supply, per-stage concentration, ownership resolution and the demand lens - the full method is illustrated live on copper, nickel and lithium.

Read the methodology, illustrated live →