The data
The data come from CEPII BACI (Etalab 2.0 licence), which reconciles what the exporting and the importing country report, in current USD, FOB.
The figures on each page are for the latest available year and the historical series goes back to 1995. Values are those of the database and are not adjusted for inflation, so a comparison between distant years mixes price and volume changes.
What dependence is
Dependence is the share of a country’s imports (or exports) that each partner accounts for. It does not measure whether a product has a substitute or how much it would cost to change supplier.
A partner’s share is what the country buys (or sells) to that partner divided by the total of its imports (or exports) for the year. The ten largest partners on each side are shown.
The concentration index
The concentration index (HHI) adds up the square of each partner’s share, in percent: it runs from 0 to 10,000. Its equivalent is 10,000 ÷ HHI, the number of partners of the same size that would give that value.
A value close to 10,000 means almost everything comes from a single partner; a low one, that trade is spread across many. The compared concentration table ranks countries by this index and the page says how far above or below the median of all of them it is.
Products with a dominant supplier
A product has a dominant supplier when a single country sells more than 50% of what is bought of it; we flag it separately above 75%.
Products are HS4 headings of the 1992 nomenclature (some combine different goods), with a floor of $1 million per product and country.
For each country we count the products it buys for more than $1 million; of those, the ones with a supplier above 50% and the ones above 75%. The figure “bought from the dominant supplier” adds up, product by product, what the country buys from whoever dominates that product, and divides it by all of its imports. It is not the total of those products bought from every country.
The European Union
The EU is the 27 current members in every year; the United Kingdom is outside the EU throughout the series.
The EU here is the 27 current members in every year: the series before 2004–2013 includes countries that were not yet members, and the United Kingdom counts as outside the EU throughout the series. The series for Luxembourg starts in 1999 because BACI combines Belgium and Luxembourg until 1998.
The bloc page measures only what the EU buys and sells outside the Union; on each member’s page, a separate section repeats the reading without trade inside the EU.
Re-exports and origin
Re-exports: countries that act as redistribution hubs carry their notice and the figures are not corrected.
Some of these goods may have been produced in another country: countries record origin in different ways.
What they do not say
A high share for one supplier does not by itself indicate risk: we do not measure whether other sellers exist, how much switching would cost or whether the buyer produces the good. To size it up, the country × supplier pages show how much the rest of the world exports of each product. Small countries and re-exporting hubs have more volatile figures because a few transactions change the split.
Sources and method
Sources and licenses
- CEPII BACI · Licence Ouverte Etalab 2.0
- Natural Earth · Public domain
Methodology
The data come from CEPII BACI (Etalab 2.0 licence), which reconciles what the exporting and the importing country report, in current USD, FOB. Data up to 2024.