{
  "name": "Sourcing Diversification Tracker: U.S. Manufacturing Import Concentration",
  "slug": "us-manufacturing-sourcing-diversification",
  "version": "2.0.0",
  "url": "https://www.mfgcalcs.com/signals/diversification",
  "formula": "For each family-year, named-source HHI floor = sum over retained source countries of (customs-value share of the year's true family total, in percent) squared, capped at 10000. The move is the latest floor minus the base floor; the base is exactly 2018 where available, else the family's first tracked year (each row names its own baseYear). The legacy trend field describes only that floor: falling by at least 200, rising by at least 200, or steady otherwise. It does not establish the direction of full-market HHI when either endpoint board is incomplete.",
  "bands": "The legacy band applies to the latest named-source HHI floor: diversified < 1500, moderately concentrated 1500-2500, highly concentrated > 2500. When the board is incomplete, this is a floor band rather than a full-market classification.",
  "unit": "named-source HHI lower bound, 0-10000.",
  "source": "U.S. International Trade Commission (USITC) DataWeb per-family, per-country annual customs value.",
  "provenance": "Derived entirely from USITC DataWeb, a work of the U.S. government in the public domain. Redistributable. Uses the same per-year HHI helper as the Reshoring Readiness Index.",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "MFG Calcs (mfgcalcs.com), compiled from USITC DataWeb open data",
  "caveats": [
    "The HHI rests only on NAMED source countries in the DataWeb board; a residual 'all other' tail is not itemized, so the index is a floor on true concentration.",
    "A change between two HHI floors does not by itself establish that full-market concentration moved in the same direction; endpoint coverage can also change.",
    "Concentration is a supply-risk read, not sourcing advice. Validate against your own supplier, capacity, and landed-cost numbers."
  ],
  "asOf": "2025"
}