Investigating the Causes of the Collapse of the Medieval Monetary System and Clarifying the Mindset of the Common People

My specialization is medieval economic history, and I am currently researching the collapse of the monetary system that occurred from the 15th to the 16th centuries.

Metal currency was used in ancient times, but it temporarily disappeared in the 10th century. Afterward, rice and cloth served as currency, but from around the end of the 12th century, imported coins (*toraisen*), mainly from China, came into use. It is likely that with economic development, a more convenient metal currency became necessary. Various coins issued by successive Chinese dynasties circulated, and each coin was valued at one *mon*, regardless of its type. In today's terms, this would be worth about 100 to 150 yen.

Since this currency was not officially issued by the government, the Imperial Court initially tried to ban its use, but was unsuccessful. The imported coins became firmly established and circulated throughout society. The strength of this societal autonomy is also an interesting aspect. Even though the value of the metal in the coins themselves was less than one *mon* and the government did not guarantee their value, everyone accepted their value and used them.

However, in the 15th century, the monetary system collapsed. Exploring the causes of this collapse is a major theme of my research. I am currently focusing on the issue of production. Archaeological materials and other sources show that mass production was beginning in various parts of Japan at that time. For example, Echizen ware, which could be mass-produced, emerged to replace Suzu ware from Noto, and Seto ware also began to be fired in large kilns. I hypothesize that the spread of mass production changed the economic structure and may have influenced the collapse of the monetary system. To test this hypothesis, I am examining historical documents and archaeological materials from various regions from the 15th to 16th centuries.

What is interesting when examining economic history is how the perspectives and ways of thinking of ordinary people emerge. For example, there was a certain casualness in how they trusted imported coins as currency, despite the lack of a government guarantee or significant backing from the material value of the coins themselves. There may be parallels here with the issue of subprime securities, which triggered the recent Great Recession; they also gained trust on ambiguous grounds and were purchased by many people.

In the future, while continuing my research on the medieval economy, I also hope to elucidate the thinking of medieval people. This is slightly different from what is known as the history of thought, but I hope to get closer to the standard modes of thought of the common people—how they perceived money and their ways of thinking.