Interview with researchers 21 Analyzing disparities with
the aim of realizing
equitable social systems

Changes in the perception that “all Japanese are middle class:” Delineating disparities between families and among husbands and wives

One sees signs of disparity issues in numerous aspects of society, including income, education, geographic regions, healthcare, and more. Dr. Sakoda is researching inequalities in social systems from this point of disparities. One particular focus of her research is the disparities occurring in relationships between families and married spouses. “Japan became a highly homogenous society from the mid-1970s into the 1980s. This was a period of the so-called ‘all Japanese are middle class’ shared mentality. Families enjoyed similar lifestyles, including in education levels and living standards, with considerable overlap in lifestyles and career designs. Meanwhile, during the 2000s, Dr. Toshiaki Tachibanaki (my research advisor during my university years) argued about the ‘collapse of the all-middle-class’ society. This deepened my interest in the processes transforming the lifestyles that up to then had been considered ‘normal,’ as well as in the impacts of those changes on income distribution. Today, I continue my research on the themes of inequality and poverty from the perspectives of social systems.”

Male employment became unstable from the 1990s onward, and Japanese women made advances in higher education achievement and higher income. This is thought to have caused changes in the lifecycles and family structure in Japan, including marriage, divorce, childbirth, and child-raising. Dr. Sakoda, using data analysis, made this clear in her book, co-authored with Dr. Tachibanaki, A Society of Marital Disparity: The Structure of the Bipolar Marriage (published by Chuokoron-Shinsha in 2013) (Photo 1, book at left). “Prior research on married couples were chiefly surveys based on education history, high school and university graduation, etc. We took that further, down to the specific schools each partner had graduated from, for a more fine-grained understanding of the changes occurring among married couples.” The picture emerging from survey results was that men who graduated from Japan’s elite schools* married women who were not affiliated with their own (i.e., the men’s) universities; rather, they selected as their wives women from a variety of academic backgrounds and schools. Conversely, around 60% of those who had graduated from one of the elite schools and were married had spouses who were also graduates of the same elite schools.Looking at the case of employment type, a high percentage of women were married to men with similar backgrounds; for example, approximately 60% of the husbands of women doctors were themselves doctors. This fact resulted in a “bipolarization” of income for wife and husband. The authors clarified the wife’s point of view in this situation towards her husband, which raised issues about the income distribution system. As part of this discussion, this book was first in Japan to use the term “power couple.” The response was major, and the book went through three printings in the first two months after publication.

*Here, “elite schools” are defined as one of the seven (7) universities established in Japan by the Teikoku Daigakurei (Imperial University Ordinance, promulgated in 1886, which included Hokkaido, Tohoku, Tokyo, Nagoya, Kyoto, Osaka, and Kyushu universities), to which are added two other schools, Hitotsubashi University and the Tokyo Institute of Technology (since 2024, the Institute of Science Tokyo, created from a merger between the Tokyo Institute of Technology and Tokyo Medical and Dental University).

Thereafter, the authors used prior research and fresh data to present considerations on the end of the marital relationship, namely divorce. The results were published in their next book, The Economics of Divorce: The Logics of Love and Separation (Kodansha Gendai Shinsho, 2020) (Photo 1, middle book). This was followed by Dr. Sakoda’s next co-authored book, Infidelity: The Complete Picture from Empirical Analysis (Chuokoron-Shinsha, 2023) (Photo 1, book at right). This book presents the actual status of contemporary marital infidelity, based on the results of a large-scale internet survey of married persons, and shines light on what actually occurs in a married couple—what may be called the smallest unit of society—and describes the disparities fostered as the result of these occurrences. This theme, which many find to be of close personal interest, is presented and understood through detailed empirical analysis, and the results offer a vivid picture of actual trends in Japanese society.

Exploring the gaps between “effort” and “environment” in inequalities of age, sex, disease, and more

Dr. Sakoda’s research has focused not only on the gap between married couples, but also includes studies on disparities in income, healthcare, etc. Dr. Sakoda’s factor analysis of inequalities resulting from the self-pay rate for medical expenses was published in her paper, “The Global Financial Crisis and Healthcare Inequality in Japan.” Here, she focuses on the economic cycle to verify whether changes occurred to healthcare access (under Japan’s Universal Health Insurance System) during economic recession. The period studied was 2008-2017 . According to Dr. Sakoda, expenditures on healthcare by the wealthy class (defined here as the top 20% income class) exceeded their needs, while said spending by the poor (the bottom 20%) was far less. The healthcare disparity gap was especially large for the generation currently working. Here, the effects were not limited to the poor but extended to people with incomes at the middle-level (30%-60%) refrained from accessing healthcare due to their inability to pay healthcare fees. “We found that even with Universal Health Coverage, people at lower income levels were not able to access necessary healthcare. Our study verified the period from 2008 through 2017, with the Lehman Shock* and the world financial crisis thereafter. We plan a follow-up study that extends the period so as to cover the coronavirus pandemic era as well.”

*The global financial crisis triggered by the 2008 stock market crash and the Lehman Brothers bankruptcy.

Another domain studied by Dr. Sakoda is income disparity. One factor often indicated in discussions of income disparity is the efforts made by each individual. However, one must also consider the environmental factors that are very difficult for an individual to change. Dr. Sakoda emphasizes that the support provided by systems is essential when it comes to these environmental factors. She presented her observations focused on the effects on income caused by factors that are determined by birth, including sex and age, in her paper “Estimating economic unfairness in Japan and policies toward fairness.” She says, “In Japan, men born to a single mother will, regardless of any efforts such men may make, have an income that is lower than those of other men in their similar age group. This is an unfair state of affairs, and my paper urges the need for dedicated support for such men.”

Dr. Sakoda is also concerned with the social safety net for persons born with an innate disease or disability. Her current focus is on persons with type 1 diabetes. “Type 1 diabetes is characterized by a lack of insulin production due to the destruction of beta (β) cells in the pancreas, which leads to abnormal elevation of blood-sugar levels. I hear that this disease is caused by autoimmune mechanisms and has nothing to do with genetic inheritance or with the daily life habits of the patient. So here is an illness that has nothing to do with personal ‘effort’ while, at the same time, has elements that impact monetary income. By studying persons with type 1 diabetes, my aim is to contribute to more equitable social welfare protection, including redressing income disparities caused by environmental factors.”

Research on issues in the developed nation of Japan to feature on the global stage

Dr. Sakoda was born in Hiroshima. Her grandmother suffered radiation exposure when she arrived in Hiroshima two days after the atomic bombing. Nevertheless, she never received official Certification of Atomic Bomb Sickness and was never issued a Hibakusha (Atomic Bomb Survivor’s) Health Handbook. Actually, her grandfather was also the victim of that. She has spent herlife surrounded by people whose lives were totally changed by the atomicbomb. From her childhood, Dr. Sakoda has asked herself why some people are fortunate while others are not. This was the impetus for her current interest in tackling the issues of equity, inconsistencies, and disparity.

Dr. Sakoda’s research thus engages with problems faced directly by the advanced nation of Japan. She plans to use her body of results to perform joint comparative research on an international scale, with the aim to further enhance and extend her findings. Now she has joint work with France, where she studied abroad during her university days. “Our economy has remained stagnant while prices have been high. Yet compared with other countries, disparities in Japan rarely rise distinctly to the surface. For these and other reasons, Japan is considered to be a deeply interesting country. Once I submitted a paper called ‘Why Japan’ which was bluntly rejected, but now I have a strong feeling that papers of that type, as well as related joint research, will be eagerly accepted. That gives me strong incentive to move forward.”

Dr. Sakoda seeks to uncover and elucidate diversity from a variety of perspectives, including among married couples, in healthcare and income, etc. With high anticipation, we look forward to her findings, which are sure to come when we see her continued pursuit of true “equality.”