{
  "slug": "tt008.gateway.value-density-scissor",
  "name": "Import vs export value density, by gateway",
  "unit": "ratio",
  "horizon": "long",
  "grade": "reported",
  "grade_means": "Counted and published by a named body — for this ledger, the US Census Bureau. We mirror it and keep every revision.",
  "description": "Containerised import customs value per kg divided by the same for exports, at the same port in the same month. Above 1 means the port takes in goods worth more per kilo than it sends out. Every US gateway does, from about 1.0x at New York to 4.1x at Tacoma — which is why a box that arrives full often leaves empty. Textbook qualitatively; not published as a monthly measurement.",
  "instrument": {
    "id": "TT-008",
    "name": "Port ledger",
    "clock": "medium",
    "role": "witness",
    "source": "US Census Bureau, intltrade/imports/porths",
    "source_url": "https://api.census.gov/data/timeseries/intltrade/imports/porths"
  },
  "coverage": {
    "from": "2024-01",
    "to": null
  },
  "publishable_ranges": [],
  "status": "suspended",
  "withdrawn": {
    "since": "1970-01-01",
    "until": null,
    "reason": "MOVEMENT NOT YET INTERPRETABLE. The LEVEL is sound — every gateway imports goods worth more per kilo than it exports, and measurement bias is common-mode across the two sides. But the ratio has moved 2.03x (May 2024) to 2.02x (May 2025) to 1.83x (May 2026), and at this aggregation that is indistinguishable from a shift in the commodity mix. Publishing the trend would revive exactly the bias Census abandoned the method for in 1989. Lift once the HS6 within-commodity series can decompose the move into a within-line component and a mix component, and the two are published side by side.",
    "finding": null
  },
  "citation": "Trimtabist TT-008 Port ledger, from US Census Bureau porths. Containerised customs value divided by containerised shipping weight. NOT a price index: Census discontinued its own unit-value indices in 1989 for composition bias. Method: portledger/METHOD.md. Grade: reported.",
  "citationShort": "Trimtab TT-008 Port ledger, \"Import vs export value density, by gateway\" (retrieved 2026-08-06).",
  "licence": "CC BY 4.0",
  "retrieved_at": "2026-08-06T13:46:36.118Z",
  "urls": {
    "page": "https://trimtabist.com/series/tt008.gateway.value-density-scissor",
    "csv": "https://trimtabist.com/series/tt008.gateway.value-density-scissor.csv",
    "metadata": "https://trimtabist.com/series/tt008.gateway.value-density-scissor.metadata.json"
  }
}