My IntegrationGPJS Staff Interviews

My goal is to explain the activities of people
and businesses during
disasters and wars
the help of previously unexplored data.

Graduate School of Economics and Management
Tohoku University, Associate Professor

YUKI Takenobu

The data on stock prices before and after the Great Kantō earthquake as a key to measuring the impact of the disaster on business management

My main research fields are Economic History and Management History of Japan, with a focus on Japan before the Second World War. How do people and business enterprises operate at the time of great social upheaval, for instance, after a large-scale natural disaster or during a war? What is the impact and significance of these periods of dynamic change? Answers to these questions are not clear even to those directly involved. Even as a bachelor student of Economics, I felt that looking into these topics would constitute an interesting research inquiry from the viewpoint of social sciences. At first, I was interested in the macroeconomic dynamics theory, which analyzed dynamic changes in society, but later in my undergraduate years I realized that an examination of such changes must be rooted in thorough historical research. Accordingly, in the graduate school I shifted towards the fields of economic and management history.

Our recent joint research project* with Professor Suzuki Shiba of Seikei University Faculty of Economics involves an empirical analysis of the impact an unpredictable disaster such as the Great Kantō earthquake had on business management and the corresponding price changes in the stock market. Two considerations motivated our inquiry: first, we knew almost nothing about the state of the stock market in the prewar years; second, we wanted to learn how that unforeseeable catastrophe affected the stock market and business operations.

For this project, we examined price fluctuations of sixty-two stocks whose Tokyo Stock Exchange prices consistently appeared in newspapers before and after the earthquake. Our analysis revealed that companies with factories in the disaster-stricken area were affected differently, even when they belonged to the same industry. Some of them, like Fuji Gasu Bōseki, suffered a drop in stock prices, while others, such as Kanegafuchi Bōseki, experienced a rise.

* “Kantō daishinsai to kabushiki shijō: Nichiji, kobetsu meigara dēta ni yoru bunseki” [The Great Kantō earthquake and stock market: An analysis of daily prices of individual stocks], in Japan Business History Review, 1-2 (2022), pp. 3–26.

Approaching endless wars and conflicts from the standpoint of economics

Existing empirical research usually argues that the disaster has not significantly affected the stock market. This probably results from focusing on indices such as average stock price, or on industry- rather than company-level stock prices. That is, when prices of all stocks are added up to find an average, pluses and minuses offset each other, even though the price may rise or fall depending on a company.

Our research, on the other hand, included a test for structural break, using this econometric method to confirm whether the occurrence of disaster became a starting point for changes (known as a structural break) in the behavior of stock prices. At the same time, we studied historical records to understand the management environment of the time, which formed the background for companies’ operations. The results showed that while some companies had to reduce their production capacity because of the damage caused by the earthquake, this in itself became a good opportunity for their rivals to increase their profits in the competitive market. Furthermore, outcomes of this competition among companies were factored into the price formation on the stock market.

The value of this unconventional approach to business history was recognized in 2023, when our paper received the Best Paper Award (Main Prize) from the Business History Society of Japan. Our current joint research project with Professor Suzuki highlights yet another dynamic force in society — war. Under the wartime planned economy, the Japanese government applied variously contorted principles to move around people, things, and finances. It is important, however, that investors continued their cunning operations even in this heavily controlled environment.

During the war, the government set up a system that prioritized and stimulated the allocation of funds and resources to the military industry. However institutional investors such as life insurance companies were also actively committing money to military enterprises. As a result, the profit from asset management remained almost the same before and during the war. As a saying goes, “It is difficult to end a war once started.” Wealthy citizens supporting institutional investors would probably have pressed the government to surrender, had the majority seen their fortunes rapidly dwindle as the war situation grew worse. But our research revealed that these citizen investors were actually raising considerable profits and did not risk losing their finances if the war continued. Why did the war drag on even in the face of a certain defeat? Approaching this question from the point of view of economics might help us solve the problems faced by the contemporary world, which is still plagued by wars and conflicts.

The approach to the primary materials changed through the encounters with other research fields

I have been involved in the International Graduate Program in Japanese Studies (GPJS) right from the planning stage. My fields of specialty, economic history and management history, both intersect with the disciplines of economics, management, and history. We employ empirical methods of historical research to gather factual information and utilize the framework of economics and management to examine and discuss the meaning of the derived data. In other words, there is no clearly defined and specialized discipline of economic or business history: both must constantly collaborate with other fields of study. The GPJS’s project of creating a new interdisciplinary area of Japanese studies was therefore very much in line with my own research.

It was fascinating to learn that researchers whose inquiry dealt with Japan were recruited across all Humanities faculties and graduate programs. Studying economic and business history of Japan as a member of Tohoku University Graduate School of Economics and Management, I rather welcomed the opportunity to come in touch with other disciplines such as literary studies, art history, and linguistics, and get acquainted with scholarly thinking and research methods different from my own. Furthermore, the opportunity to learn new things through work was also extremely appealing. GPJS offers many opportunities to encounter other research areas, starting with the annual Tohoku Conference on Global Japanese Studies. Presentations from other disciplines are often completely unexpected and surprising ― another great advantage of being a GPJS member.

My approach to the primary sources on economic and management history has also changed greatly since I joined the GPJS. We mostly study textual documents, carefully reading and interpreting them against their historical background. But unlike a document, a Buddhist statue, for instance, cannot itself say for what it means. When a Buddhist art scholar examines it as one of the primary sources, she must utilize her knowledge of the art history and even do a CT scan to learn the internal structure of the statue. Discovering such unique research styles and methods allowed me to get free from stereotypes, broaden my outlook, and develop a more flexible approach to my own sources. This is another benefit of my joining the GPJS. I believe that the principal objective of our program is to elevate not only research but education as well by embracing the multitude of methodologies.

The GPJS educational program as the means to expand interdisciplinarity and achieve internationality

GPJS is an attractive program not only for researchers like myself but also for graduate students. One of its advantages is the mentorship system. Besides an academic supervisor from their respective graduate school, each student receives mentorship from another teaching staff member. One of my doctoral students has a mentor who specializes in political science. The student in question studies the relationship between the petrochemical industry enterprises and the government in postwar Japan. Obviously, they must pay close attention to the development of industry, as well as approaches informed by economics and management studies. But political science also plays an indispensable role in their research, considering the enormous impact of political processes on industrial policies. The student is also well aware of this, so they regularly consult with their mentor who offers them feedback from the political science standpoint. In other words, by joining the GPJS program, this student has gained new knowledge they would not have been able to acquire at the Graduate School of Economics. The scope of their research has positively grown as a result.

Another great aspect of the GPJS program is its ‘internationality.’ The students I supervise have been able to broaden their thinking by presenting at various universities overseas. I myself have also encountered novel ideas different from those developed by researchers in Japan. Some widely shared assumptions might seem much less obvious when seen through the eyes of a foreign researcher. I often get questions about such ‘established truths’ when I publish or present my findings outside Japan. When we share our discoveries with our foreign colleagues, find issues in the need of clarification, and engage in further discussion, not only does it develop the international exchange, but it also helps us to relativize and therefore advance our own research. I hope that you will use the GPJS program to embark on a literal quest for knowledge and develop ever more nuanced approaches to various contemporary issues.

  • Associate Professor, Tohoku University Graduate School of Economics and Management.
    Ph.D. (Economics) (The University of Tokyo), Master (Economics) (Osaka University)
    Completed the Graduate School of Economics, Osaka University in 2007, and the Graduate School of Economics, The University of Tokyo in 2014.
    After working as an assistant professor at Shumei University and a full-time lecturer at the same university, he has been in his current position since 2015.
  • Main Fields of Research: Japanese economic history, Japanese business history
  • Researcher Information, Tohoku University