Verify a number yourself
ETRX has no authority except that anyone can check it. Here is how to reproduce a published value from the government's own data in a few minutes.
Worked example: China — electronics (HS 85), August 2026
ETRX printed 21.41%. The two inputs behind it:
Route 1 — the Census API (one URL)
The calculation code is open source: github.com/svnbanker/etrx-engine. Clone it, run the selftest, and print a month yourself.
Get a free key at api.census.gov/data/key_signup.html (instant, email activation), then open:
The row returned carries CON_VAL_MO and CAL_DUT_MO. Divide. You will
get the number above to the last digit, unless Census has since revised the month —
in which case the difference is exactly what our revisions log records.
Route 2 — USITC DataWeb (no key, point and click)
- Open dataweb.usitc.gov → Trade data → Imports for consumption.
- Data to report: Customs value and Calculated duties. Timeframe: monthly, August 2026.
- Commodities: HTS 2-digit, chapter 85. Countries: China.
- Run the report; divide calculated duties by customs value.
What "matches" means
Aggregates (the headline, steel, pharma, apparel) sum dollars across chapters before dividing; check them by summing the chapter rows. The headline excludes chapters 98 and 99. Every published value is stored to six decimals; displayed values are rounded to two. The full formula set and all edge rules are in the methodology.