The ledger of rebellion
The Takayama Jinya was a government outpost, the administrative center for Hida Province during Japan's Edo period. In 1692, the Tokugawa Shogunate placed the resource-rich province under its direct control. For the next 177 years, officials dispatched from Edo (modern-day Tokyo) governed from this building complex, managing everything from legal disputes to public works.
A primary function of the Jinya was collecting the annual rice tax, or nengu. Rice was the foundation of the feudal economy, and taxes were paid in bales, not coin. These payments were recorded in meticulous ledgers and the rice itself was stored in a massive storehouse, or kura, on the Jinya grounds. This granary, built in the 1600s, is one of the largest of its kind still standing in Japan. The documents stored here created an unintentional dataset, a year-by-year record of the region's economic output, detailing harvest yields, tax assessments, and official correspondence for nearly two centuries.
From data to prediction
These historical ledgers are now a source for cliometrics, the field of economic history that uses quantitative analysis to study the past. Researchers analyze the Jinya's tax archives as a long-term dataset to find patterns in the interplay between the economy and society. The data allows for a statistical examination of the causes of peasant uprisings, known as hyakushō ikki, which occurred periodically throughout the Tokugawa era.
The analysis correlates specific data points from the records: annual rice harvest volumes against the dates of documented peasant revolts in the province, such as the Ohara Rebellion which began in 1771. The core finding connects poor harvests, often due to factors like cold weather, with an increase in social unrest. When yields fell, the fixed tax rate consumed a larger portion of the farmers' production, sometimes reaching levels as high as 70 percent of their yield. The Jinya's archives provide the raw data that shows a direct link between food scarcity and organized revolt. This application of modern data science to historical records transforms the old tax office into a laboratory for understanding the economics of rebellion.