Bunsei Chōgin (文政丁銀) — The Economic Shadow Closing In on the End of Edo

In 1819, Bunsei 2, the shogunate issued the Bunsei Chōgin. The backdrop was the severe fiscal deficit the Edo shogunate was carrying at the time. In the latter part of the Edo period, well before the Tenpō Reforms began, the shogunate's finances had been deteriorating, and the outflow of silver from within Japan had become a particular problem. With silver growing scarce due to the effects of trade, the shogunate devised a strategy of reducing the purity of other gold and silver coins in order to increase revenue. The silver purity of the Bunsei Chōgin stood at about 36% (per the Currency Museum catalog), a figure that represented a dramatic drop from the approximately 80% of the Keichō Chōgin. The shogunate sought to stabilize the economy by tightening its control over the Gold and Silver Mints and increasing minting volumes, but this policy brought only short-term fiscal improvement. What the shogunate faced was the formidable challenge of maintaining the economy without forfeiting public trust. Minting operations at the Silver Mint magistracy (銀座奉行所) had reached the limits of available refining technology, and many craftsmen confronted that difficulty head-on. Although the Bunsei Chōgin resembled the Keichō Chōgin in appearance, its weight and purity differed markedly, and the trust of merchants began to waver. In this way, the Bunsei recoinage was carried out as part of the shogunate's fiscal policy, yet it also served to create new sources of economic instability.

Minting of the Bunsei Chōgin was conducted primarily at the Silver Mint magistracy in Edo. There, craftsmen worked day and night on the refining of silver. In the production process of the Bunsei Chōgin, work proceeded according to mixing ratios directed by the shogunate, adding copper and lead to silver to lower its purity. This work was extremely difficult given the technical standards of the day, and many artisans spent their days in repeated trial and error. In order to maintain silver purity while reducing costs, they repeatedly reviewed their raw materials. What emerged from this process was the distinctive composition of the Bunsei Chōgin, resulting in a silver purity reduced to about 36%. This was a figure less than half of the approximately 80% high purity that the Keichō Chōgin had boasted, representing the culmination of monetary debasement stretching back to the early Edo period. The Bunsei recoinage of Bunsei 2 (1819) was also linked to the concurrent debasement of the Bunsei Koban, and with both gold and silver coinage losing value simultaneously, it dealt a double blow to the Kamigata economy. Money-changers and merchants in Osaka were confronted by sudden swings in the gold-silver exchange rate and found themselves compelled to question the very reliability of the currency that served as the standard for their transactions. Although silver supply did increase as a result, monetary credibility declined and it became a factor destabilizing silver exchange rates in the market. Minting at the Silver Mint magistracy played an important role as part of the shogunate's economic policy, but behind it lay much hardship and inner conflict. There was also a deceptive aspect: while the coin retained an external shape closely resembling the Keichō Chōgin, it was substantially inferior in both weight and purity — a circumstance that, according to various theories, is said to have made it difficult for the general public to distinguish between the two. The Bunsei Chōgin subsequently circulated as the primary silver coin supporting shogunate finances for approximately 18 years, until the Tenpō Chōgin was minted and put into circulation in Tenpō 8 (1837). The technicians of the day endeavored to meet the shogunate's exacting demands while striving to contribute to economic stability.

The appearance of the Bunsei Chōgin delivered a severe shock to merchants. In particular, the Kamigata merchants of Osaka, then the economic center of Japan, harbored deep misgivings about this debasement of the currency. They conducted their commercial transactions using the Keichō Koban and Keichō Chōgin as benchmarks and took issue with the fact that the value of the Bunsei Chōgin was markedly inferior by comparison. Whereas the silver purity of the Keichō Chōgin had stood at approximately 80%, the Bunsei Chōgin issued through the recoinage of Bunsei 2 (1819) had seen its purity fall to a mere 36% or so — less than half. Moreover, the Bunsei Koban issued at the same time also underwent debasement, making it a double blow to the Kamigata economy as both gold and silver coinage deteriorated simultaneously. After the Bunsei Chōgin entered circulation, merchants struggled with how to set its exchange rate. Because its outward appearance closely resembled the Keichō Chōgin, verifying weight and stampings anew upon receipt became necessary, and it is said that confusion spread even at Osaka trading venues including the Dōjima Rice Exchange (堂島米会所). In the market, the value of silver grew unstable and price fluctuations became frequent. In the Edo market as well, commodity prices rose and directly affected the lives of ordinary people. Specifically, prices of daily necessities such as rice and cloth soared, and the lives of commoners fell into dire straits. The shogunate attempted to stabilize the situation by fixing currency exchange rates, but could not dispel the distrust among merchants and ended up increasing the instability of the economy as a whole. Such turmoil continued for approximately 18 years until the transition to the Tenpō Chōgin in Tenpō 8 (1837), and among various theories there exists the view that this situation was not unrelated to social unrest exemplified by the Ōshio Heihachirō Rebellion (大塩平八郎の乱) of Tenpō 8 (1837). In this way, the Bunsei Chōgin came to symbolize the failure of the shogunate's fiscal policy, transcending its role as mere currency. The reaction of merchants exceeded the shogunate's intentions and became the trigger for a major destabilization of the economic framework.

In 1837, Tenpō 8, the shogunate carried out another currency recoinage, transitioning from the Bunsei Chōgin to the Tenpō Chōgin. The Tenpō Chōgin was issued as an attempt to raise silver purity once again, and behind this lay the various problems that had been exposed by the Bunsei Chōgin. Through this recoinage the shogunate attempted to restore trust, but among merchants a deep sense of distrust had already taken hold. The issuance of the Tenpō Chōgin brought a temporary calming of market confusion, but no fundamental resolution was achieved. The shogunate's monetary policy continued to lose credibility through the repeated recoinages that had been carried out. Later historians have frequently viewed the failure of the Bunsei Chōgin as a symbolic event in the shogunate's decline. As a result, Japan's monetary system was compelled to undergo major reform on the road toward modernity. From the end of the Edo period through the Meiji Restoration, Japan became incorporated into the international economic sphere as imports and exports increased. In this process, the lessons learned from the experience of the Bunsei Chōgin and Tenpō Chōgin were put to use in the construction of a modern monetary system. By comparing these historical backgrounds with the details of Edo silver coinage, one can gain an understanding of the impact of monetary policy of the era.