{
  "study_id": "2026-09-23-china-upstream-exposure",
  "frozen_at_utc": "2026-09-24T01:28:57.986457+00:00",
  "freeze_precedes_data_acquisition": true,
  "observation_year": 2022,
  "edition": "OECD regular ICIO 2025 edition, second revision mid-January 2026",
  "exporters": [
    "JPN",
    "KOR",
    "DEU"
  ],
  "industries": [
    "C26",
    "C27",
    "C28"
  ],
  "comparison_origins": [
    "CHN",
    "USA"
  ],
  "unit": "to be verified in official ReadMe before analysis",
  "denominator": "Gross exports of each exporter-industry to all foreign intermediate and final uses; domestic uses and total columns excluded",
  "estimator": "Full-global-system origin value added via A=Z diag(x)^-1; solve (I-A) q=e; origin sum of (v/x)*q divided by exports",
  "cell_count": 9,
  "aggregation": "Report all cells separately; no coalition sum",
  "uncertainty": "No manufactured confidence intervals for a single accounting table",
  "limitations": [
    "Historical 2022 accounting, not a 2026 dependence measurement",
    "Not causal bottleneck, substitutability, supplier qualification, ownership, military suitability or wartime access evidence"
  ],
  "tolerances": {
    "solver_max_abs_relative_to_rhs": 1e-10,
    "all_origin_reconciliation_with_explicit_tax_and_rounding_relative": 1e-09,
    "source_rounding_balance": "Derived from published precision and count of summed cells, declared before computing estimates"
  },
  "preflight": "Use official OECD ICIO and established NumPy/SciPy/pandas/matplotlib numerical tools; no custom platform"
}