Japan's earthquake and Thailand's floods cut parts supply

Reading the numbers

Documented context for the figures above that run against the event’s headline. The measurements stand as they are; each item cites its sources.

An annual view: 2011 holds the quake's March–May trough in Japanese vehicle output (292,044 in April against 706,107 in January, 742,531 by June) and the floods' October–December stop in Thailand, beside the months in between; the base year 2010 was itself a rebound (world car-parts trade +29.4%). In the series on this page Japan's car-parts exports rose a further 6.8% in 2012 and Thailand's 28.8%.

1. Prices and exchange rates

   Japan's car-parts exports +12.0% ($37.3bn → $41.8bn, 2010 → 2011). The dollar figures carry the yen's rise: the yen averaged 87.78 per dollar in 2010 and 79.70 in 2011. In yen, Japan's customs statistics show exports of parts of motor vehicles falling 2.8% in 2011 to ¥2,997bn after a 33.5% rise in 2010, with shipments to the US down 2.9%, to China 4.2% and to ASEAN 5.3%. [6] [7] [8]

2. Business cycle

   Japan: 13.3% → 12.6% of world car-parts exports (−0.7 pp), the largest fall among the movers. Vehicle production in Japan fell to 8,398,654 in 2011 from 9,628,920 in 2010. The fall was concentrated in spring: transport-equipment output in March was 46.7% below February (seasonally adjusted), and monthly vehicle output was 403,937 in March and 292,044 in April against 706,107 in January, then 883,602 in September and 904,254 in October. [9] [10]

3. Product definition

   Thailand's car-parts exports +7.8% ($3.9bn → $4.2bn). Thailand's 2011 fall was in finished vehicles: production 1,457,798 against 1,645,304 in 2010 and vehicle exports 735,627 units against 895,831; the Commerce Ministry's heading for motor cars, parts and accessories together fell from €14.0bn to €12.7bn. Output fell 27.8% in April on parts shortages from Japan, and Honda's Ayutthaya plant was shut from 4 October 2011 to 26 March 2012. [11] [13] [14]

4. Substitution

   China → Japan: 28.8% → 32.7% of Japan's car-parts imports (+3.9 pp); Thailand → Japan 10.3% → 9.6%. In yen, Japan's imports of parts of motor vehicles fell 3.3% in 2011; imports from China rose 9.9% while imports from ASEAN fell 14.8% and from the EU 10.8%. The floods closed six industrial estates in Ayutthaya and Pathum Thani from mid-October to November 2011, and Thai output fell 10¾% quarter on quarter in the fourth quarter, the largest fall on record. [5] [6] [12]

Timeline

1. 11 Mar 2011Magnitude 9.0 earthquake and tsunami off the Pacific coast of Tohoku [1]
2. 25 May 2011Japan's April exports 12.5% below a year earlier; cars down 67% [2]
3. 12 Oct 2011Western Digital suspends hard-drive production near Bangkok [3]
4. 17 Oct 2011Western Digital: floods inundate its main plant, at Bang Pa-in [4]

What else changed

World exports of car parts changed +18.2% between 2010 and 2011.

No other event in the catalogue falls in the same window.

Values are in US dollars: prices and exchange rates move them as well as volumes, and this page does not separate them. None of the numbers here says why trade moved.

Documented context for the figures that run against the headline is in “Reading the numbers”, with sources.

Coverage

Sources

1. The 2011 Great East Japan Earthquake: portal (earthquake summary) · Japan Meteorological Agency · no date; accessed 24 Oct 2026
2. Japan exports sag in April after tsunami · Associated Press (via News Tribune) · 25 May 2011
3. WD reports impact on HDD production due to severe flooding in Thailand (Form 8-K, Exhibit 99.1) · Western Digital Corp. (SEC EDGAR) · 12 Oct 2011
4. WD provides update on effect of Thailand floods: primary manufacturing site flooded, second site at risk (Form 8-K, Exhibit 99.1) · Western Digital Corp. (SEC EDGAR) · 17 Oct 2011
5. Thai Flood 2011: Rapid Assessment for Resilient Recovery and Reconstruction Planning, Overview · World Bank · 1 Jan 2012
6. Trade Statistics of Japan: Value of Exports and Imports 2011 (Calendar Year, January–December), Fixed Annual · Ministry of Finance, Customs and Tariff Bureau · 13 Mar 2012
7. Trade Statistics of Japan: Value of Exports and Imports 2010 (Calendar Year, January–December), Fixed Annual · Ministry of Finance, Customs and Tariff Bureau · 14 Mar 2011
8. G.5A Foreign Exchange Rates (Annual), 2011 · Board of Governors of the Federal Reserve System · 3 Jan 2012
9. 自動車統計月報 (Motor Vehicle Statistics monthly report), Vol. 45 No. 10, January 2012 issue: four-wheel vehicle production · Japan Automobile Manufacturers Association (JAMA) · no date; accessed 25 Oct 2026
10. Indices of Industrial Production, Revised Report for March 2011 (生産・出荷・在庫指数確報 平成23年3月分) · Ministry of Economy, Trade and Industry (METI) · 19 May 2011
11. Honda Resumes Production at Automobile Plant in Thailand · Honda Motor Co., Ltd. · 26 Mar 2012
12. Public Information Notice No. 12/48: IMF Executive Board Concludes 2012 Article IV Consultation with Thailand · International Monetary Fund · 10 May 2012
13. Thailand: Automotive Hub of Asia (presentation; Thailand Automotive Institute and Ministry of Commerce data) · Thailand Board of Investment · 21 Sep 2012
14. April Economic Indicators: Sluggish Production and Domestic Spending (Business Brief No. 3118) · KASIKORN Research Center · 31 May 2011

Related case studies and chains

• Case 2 After Japan's 2011 quake, buyers switched suppliers