Published papers

This study develops a mathematical model to explain the mechanism of investments in shadow education. Many previous studies have shown that hierarchical factors such as income, occupation and educational background affect investment in shadow education. However, there is no model in the field of sociology that explains why hierarchical factors affect these investments. In this study, I apply an economics model of human capital investment theory to a mathematical model explaining the mechanism why parents invest in their children’s shadow education. The mathematical model in this study shows that parents invest to obtain utility from their children’s future income, and as previous studies have pointed out, higher income and higher educational attainment, parents invest more aggressively. In addition, parents with a hierarchical reproduction orientation invest more aggressively. The validity of the model was confirmed in an empirical analysis using the “Longitudinal Survey of Newborns in the 21st Century”.

This article reviews recent literature on wealth inequality in the field of social stratification and provides an overall picture of theories, important concepts, and findings obtained through empirical research. Max Weber viewed assets as a foundation for constituting inequality. However, inequality studies during the postwar period have largely overlooked the importance of wealth in shaping people’s life chances because stratification research conceptualized people’s so- cial class and socioeconomic status based on occupational status in the labor market. In recent years, several studies have been undertaken in Western coun- tries on wealth inequality and its impact on people’s life chances. The definition of wealth and its characteristics are discussed in this paper. We address the fol- lowing issues; How does wealth shape people’s life chances, such as education- al and occupational attainment, transition into marriage and parenthood, and living conditions among elderly people? How is wealth disparity reproduced across generations? To explain them, we propose the two models: a life cycle model and a model of intergenerational wealth reproduction. It is also suggest- ed that the model of social mobility across multiple generations is highly effec- tive in exploring reproduction of wealth inequality from generation to genera- tion.

    In Japan, the factors of having multiple children have been examined mainly in the field of demography. For example, sex preference for children, the degree of male participation in childrearing and living with three generations are pointed out as factors in a thirdchild's birth. However, the effects of parents' educational expectations and educational investment on parity progression has not been adequately examined. In this paper, this point is examined using the Longitudinal Survey of Newborns in the 21st Century (wave1-wave15). Our analysis reveals two points. First, high educational expectations for children had a significant negative effect on parity progression. Second, high educational investment in children had a significant negative effect on parity progression. These results suggest that socioeconomic differences in children's educational attainment and educational investment affect the number of children. These results can also be interpreted in terms of socioeconomic differences in strategies concerning social stratification maintenance.

This study examines which factors affect participation in telework during the COVID-19 pandemic. Inequality in access to telework is a sociologically relevant research topic because it also generates inequality in life chances in other important domains: employment, income, and health. This study focuses specifically on workers with young children because telework can produce a flexible workstyle and is very helpful to those people. The results of our analysis show that the utilization of ICT plays a critical role in explaining participation in telework. Professionals and managers are more likely to engage in telework than manual workers, and the telework participation rate in the professional service sector is higher than that of the manufacturing, construction, and agriculture sectors. In addition, the well-known factors that traditionally contribute to the expansion of inequality also affect telework participation. Workers who have graduated from university, work as regular workers, or work at large firms are more likely to engage in telework. We also explore how the intersection between occupation and industry affects access to telework and how telework participation differs by gender. Given that engagement in telework is related to inequality in the risk of infection in the COVID-19 pandemic era, we conclude that the spread of telework has reinforced existing inequality rather than alleviated it.

This paper aims to clarify the causal relationship between Chinese migrants' education and their income in Japan. I focus on the comparison between educational attainment in China and that in Japan. The result of my research shows that educational credentials obtained in Japan have a significant effect on the income of Chinese migrants and that there is a significant mutual relation between their Chinese and Japanese educational credentials in terms of income determination.