Japan has a reputation of hostility to foreigners and outside trade. But I recently learned about its brief period of openness under the Tokugawa shogunate from 1600 to 1636. There were waves of Japanese migration throughout Southeast Asia and a rise of successful Japanese merchant fleets.
In his chapter in the Cambridge History of Southeast Asia, Leonard Andaya writes "A measure of the importance of this Japanese trade was their export of silver. Between 1615 and 1625 an estimated 130,000-160,000 kilograms of silver was sold, amounting to 30-40 percent of the total world output outside Japan." (He cites Seiichi Iwao's article 'Japanese foreign trade in the sixteenth and seventeenth centuries' which I was unable to find).
It seems like Japanese traders saw fairly quick and dramatic success. But after 1636 we see trade drastically limited to a few foreign merchants in Nagasaki. I know many other countries saw foreign trade as an attractive and easy source of taxation. How could the Tokugawa shogunate turn down such a potentially lucrative revenue source?
Japan did not end foreign trade. They decided force all trade to go through Nagasaki and banned everyone not conducting trade. For the reasons for that see Why did Japan decide to limit access of the country to foreigners?
Even after the passing of such regulations, trade continued. In fact it seem to have continued to increase for a time. Iwao's estimate of 130,000 to 160,000 kg over a ten year period comes down to about 35,000 to 43,000 kanme (3.73~3.75kg of silver), or 3,500 to 4,300 kanme per year on average. This is the yearly average in Japanese exports from Nagasaki (Chinese + Dutch trade) in the mid-17th century, recorded in values in kanme:
| Years | Silver | Gold^1 | Merchandise^1 | Total |
|---|---|---|---|---|
| 1645-1654 | 10,338 | 6,296 | 16,634 | |
| 1655-1661 | 17,679 | 6,872 | 24,551 | |
| 1662-1668 | 12,557 | 7,769^2 | 5,563 | 21,453 |
| 1669-1670 | 345 | 17,330 | 6,314 | 23,989 |
^1 Value equivalent to silver kanme.
^2 The average of 1666 to 1668. The surviving figures for gold export valued in kanme are: 29 in 1664, 2,292 in 1666, 4,322 in 1667, 16,784 in 1668.
Note table does not include a small amount of value for purchase for the Shogun and court and a larger value of money of money kept in Japan for use by the traders themselves, which in 1655-1661 comes to 181 and 1,611 kanme a year on average respectively.
So in the 30 or so years after forcing everything to go through Nagasaki, the amount of silver that left Japan each year on average actually more than quadrupled. The sharp drop off in silver exports starting around 1665 was due to the fact that Japanese silver mines like those at Ishimi, Ikuno, Nobesawa, and perhaps others were all beginning to dry up. This lead the Bakufu to limit the outflow of silver to preserve them for use at home. But gold use in trade was increased to compensate and as shown above did not effect the total value of trade. Around the turn of the century Dutch trade declined, but Chinese trade grew and made up for it.
Cullen, Louis. (2017). The Nagasaki Trade of the Tokugawa Era: Archives, Statistics, and Management. Japan Review, (31), 69-104.