# Finding: incommensurable trade quantities

**Status:** corrected in the rebuild. The defect is not displayable through the
`arctic_api` view layer.

## What was wrong

The published figure ranked species by a single "Total Quantity Traded" computed
as `SUM(quantity)` over a column whose unit varies row by row. Kilograms were
added to individual animals. All fifteen species in that figure had a total that
mixed mass with counts. The resulting ranking was an artifact of which unit
yields larger integers, not a ranking of trade volume.

Separately, 226,046 of 492,095 CITES trade records (45.9%) sit inside a shipment
coordinate reported from both the importer and the exporter. A total that spans
both reporter sides counts those shipments twice.

## What the rebuild does

Trade is reported per unit dimension (mass, count, volume, length), per traded
term, and per reporter side. There is no function in the application data layer
that returns a dimensionless quantity total. That is enforced by the view
definitions and by tests, not by convention alone.

## Arithmetic check

| Claim | Value | Source |
|---|---|---|
| CITES trade records in the deposit | 492,095 | `tables/cites_trade_records.csv` |
| Records in dual-reported shipment coordinates | 226,046 | derived at analysis time from the same source |
| Share dual-reported | 45.9% | 226,046 ÷ 492,095 |
| Species in the published figure whose total mixed units | 15 of 15 | each of the fifteen top-`SUM(quantity)` species carries both a mass and a count dimension |

## Related

- Application: `/changes#no-total-quantity`
- Code: `src/lib/figures.ts`, `src/lib/queries.ts` (`getSpeciesTrade`)