Derived metric methodology, version 1.0

Copper production top-3 country concentration

Share of world copper mine production supplied by the three largest producing countries in the USGS world production table, per year.

DerivedMetric page

Specification

How the value is computed

spec hash 07384fc6296351e4

Formula in plain words

The custom function top3_share_of_world over the whole component dataset, for each geography and period. A period with any component missing produces no value. Rounded to 1 decimal.

Components

Label	Metric	Geography	Lag	Transform	Scale	Constraint
copper-mine-production	Copper mine productioncopper-mine-production, thousand metric tonsObserved	same as the output	none	level, as stored	1	none

Combination: Named function top3_share_of_world, evaluated once over the whole component dataset (it reads across geographies or records an assessment) and returning the observation ids it used.
Missing data: Skip the period: no value is produced unless every component is present. Nothing is interpolated or carried forward.
Window: None: each period stands on its own.
Normalization: None: the combined value is published in its own unit.
Unit and rounding: percent of world production. Rounded to 1 decimal, applied last.
Default geography: WLD

Coverage

What has been computed

Current values: 2
Geographies: 1
Periods: 2, 2024 to 2025
Last computed: 2026-09-07 22:04 UTC
Produced by: version 1.0

Reproducibility

Last verification

Outcome: success
Run at: 2026-09-07 22:15 UTC
Examined: 5101 derived values across all metrics, 5090 reproduced, 0 issues
This metric: 2 of 2 reproduced, 0 issues

Worked example

World, 2025

Stored value

48.7 percent of world production

Observation id: 404024
Formula version: 1.0
Source revision: v1.0/01efc0fa95e5
Computed at: 2026-09-07 22:04 UTC
Coverage: 1 of 1 components (minimum 1)
copper-mine-production: 23,000

Recorded with the value

{
  "top3": [
    {
      "name": "Chile",
      "value": 5300,
      "geography": "CHL"
    },
    {
      "name": "Congo, Dem. Rep.",
      "value": 3200,
      "geography": "COD"
    },
    {
      "name": "Peru",
      "value": 2700,
      "geography": "PER"
    }
  ],
  "top3_sum": 11200,
  "world_total": 23000,
  "countries_considered": 14
}

Component observations used

4 observations

Observation id	Metric	Geography	Period	Value	Source revision
263646	copper-mine-production	WLD	2025	23,000	MCS2026
263635	copper-mine-production	CHL	2025	5,300	MCS2026
263637	copper-mine-production	COD	2025	3,200	MCS2026
263642	copper-mine-production	PER	2025	2,700	MCS2026

Recompute by hand: The custom function top3_share_of_world over the whole component dataset, for each geography and period. A period with any component missing produces no value. Rounded to 1 decimal. Applying that to the rows above gives 48.7 percent of world production.

History

Version history

metric_method_versions

Version 1.0, effective 2026-09-07 00:00 UTCcurrent

Formula copper-top3-concentration(year) = 100 * sum(top 3 country values of copper-mine-production(year)) / copper-mine-production(WLD, year)

Copper production top-3 country concentration, version 1.0

Formula. For each year, take every country row of copper-mine-production (the USGS world production table without the world total and without the "Other countries" residual), sort by value, sum the three largest, and divide by the USGS world total for the same year. Multiply by 100.

Units. Percent of world production.

Missing data. A year is computed only when the world total and at least three country rows exist. Withheld country values are absent, not zero, so a withheld large producer would understate the share; the metadata lists the three countries used. No interpolation or smoothing.

Reading it. Higher means more of the world's supply comes from three countries and a disruption in any one of them matters more. Direction is lower is better for resilience. The share is by mine output, not by refining or by ownership, so it can understate concentration in the processing stage.

Revision. Recomputed after every ingestion of the component; a changed component value produces a new observation row and earlier rows are kept.

Source revision label. v1.0/<component release> so a value can be traced to the USGS release it was computed from.