yoshiakihayashida/japan-import-origin-concentration

Japan Import-Origin Concentration (貿易統計 HHI)

Herfindahl origin-concentration index for Japan's strategic imports — crude oil, LNG, coal, wheat, soybeans, iron/copper ore, rare earths — from official 財務省貿易統計 country-of-origin detail (2015–2024).

Why this exists

Procurement risk starts with one question: how much of a critical import rides on one country? For ten strategic imports this computes the Herfindahl-Hirschman Index (HHI) of Japan's import value across every origin, so a concentration number traces to named suppliers. Coal ~HHI 4,500 (Australia ~65%); crude oil ~3,300 (Saudi Arabia ~41%); rare earths reflect the China dependence.

Tables

File	Grain	Layer
jpn_import_origin_concentration.csv	iso3, year, hs_code, commodity, hhi, top_origin, …	L0
jpn_import_origin_shares.csv	iso3, year, hs_code, commodity, origin, origin_share_pct	L0
import_origin_concentration_jpn_vs_us.csv	iso3, country, year, hs_code, commodity, hhi, …	L1 — same HHI in a cross-country-ready shape (currently Japan)

Notes on the data

• hhi = Σ(origin value share %)², 0–10000 (procurement convention). hs_code = HS4 group.
• Commodities: 2709 crude oil, 2711 LNG/LPG, 2701 coal, 2844 nuclear fuel, 1001 wheat, 1201 soybeans, 2601 iron ore, 2603 copper ore, 2805 rare-earth/alkali metals, 8103 tantalum.

Sample queries

-- Most origin-concentrated Japanese imports, latest year
select hs_code, commodity, hhi, top_origin, top_origin_share_pct
from jpn_import_origin_concentration where year = 2024 order by hhi desc;

-- Who supplies Japan's coal — composition under the HHI
select origin, origin_share_pct from jpn_import_origin_shares
where hs_code = '2701' and year = 2024 order by origin_share_pct desc;

License & attribution

See the LICENSE file for full terms. When reusing you must:

• 出典：財務省「貿易統計」（e-Stat 経由取得）を加工して作成 (PDL 1.0 requires 出典表示 + 加工明記)