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ãJapanese Foreign Exchange Interventions, 1971-2018: Estimating a Reaction Function Using the Best Proxyã
Takatoshi Ito(a), Tomoyoshi Yabu(b)
(a) School of International and Public Affairs, Columbia University, and GRIPS, Tokyo
(b) Department of Business and Commerce, Keio University
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¥ã®åæããäŒè€éæã»è
çµæžç ç©¶ãVol.54 No.2 Apr. 2003
ãEffects of the Bank of Japanâs intervention on yen/dollar exchange rate volatilityã21 November 2004
Toshiaki Watanabe (a), Kimie Harada(b)
ãThe Effects of Japanese Foreign Exchange Intervention: GARCH Estimation and Change Point Detectionã
Eric Hillebrand Gunther Schnabl Discussion
Paper No.6 October 2003
Japanese Foreign Exchange Interventions, 1971-2018: Estimating a Reaction Function Using the Best Proxy
December 12, 2019
Takatoshi Ito(a), Tomoyoshi Yabu(b)
(a) School of International and Public Affairs, Columbia University, and GRIPS, Tokyo
(b) Department of Business and Commerce, Keio University
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4. Patterns of intervention
Fig. 3, panels (a) and (b), show monthly data of the yen/dollar rate and amounts of interventions by the Japanese monetary authorities.
Panel (a) shows the movement of the yen/dollar rate. The dotted line represents the past-five-year moving-average of the yen/dollar rate.
Panel (b) shows that in the 1970s and 1980s, interventions were very âfrequent and symmetricâ: yen-selling interventions as well as yen buying interventions were frequently conducted.

The yen had been on a long-term appreciation trend, as shown in panel (a), throughout the 1970s and 1980s.
It has been well documented that the authorities intervened in an attempt to stop this appreciation, presumably to prevent adverse effects on export industries.
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However, it was little publicized that yen depreciation was also resisted by selling the dollar.
Three hypotheses could explain the symmetric interventions.
First, the authorities genuinely believed that the long-run trend could not be resisted, yet it was the authoritiesâ role to reduce âexcessâ volatilities, upside and downside.
Second, merely resisting yen appreciation by buying US dollars, would only have resulted in ever-accumulating foreign reserves that would have been exposed to increasing evaluation losses, which could have triggered political criticism.
Third, the interest rate in Japan was similar or even higher than the US interest rate during the 1970s and 1980s; hence, building up foreign reserves meant that interest income might not cover domestic interest payments to fiscal bills that are liabilities in the foreign exchange special accounts.
The âquasi-fiscalâ costs were real concerns in Japan during the 1970s and 1980s.
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For the reasons mentioned above, whenever the yen depreciated to some extent, like in 1973 and 1979 (due to the oil crises), 1981-82, and 1989, the yen was bought back, which appears to slow the yen's depreciation and to keep foreign reserves at a reasonable level.
This attitude of symmetric interventions changed in the 1990s. After 1992, the only instance of sizable dollar-selling interventions was 1997-98 when the banking crisis of Japan caused a sharp yen depreciation.
The magnitude of interventions became distinctively large while the frequency of interventions was reduced. In particular interventions in 2003-04 and 2011 were very large.
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