Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Sociology and Anthropology

Department name when degree awarded


Committee Chair(s)

Eric N. Reither


Eric N. Reither


H. Reed Geertsen


Michael B. Toney


According to a World Health Organization report, about one million people die by suicide each year. Fortunately, rates of suicide mortality have been decreasing
among most of the OECD countries, but Japan and South Korea are the only two exceptions to this trend, which has shown increasing suicide rates over the last 25
years. A number of studies have focused on psychological motives and individual-level causes of suicide, such as depression, mental disorder, and disability. However,
as Durkheim pointed out, suicide in a society does not have any obvious relationship to the prevalence of mental disorder. With his theory indicating that suicide is a social
phenomenon that needs to be explained in a social context with social determinants, this study aimed to understand the effects of three types of time-related socio-
demographic variables (age, period, and cohort) on suicide in Japan and South Korea.

This study focuses on (1) the relative contribution of age, period, and cohort effects on suicide in each country and (2) the comparison between the impact of the
three effects on changes in suicide rates. I thought that it would be potentially significant concerning the increasing suicide rates in the two countries that Japan and
South Korea are neighboring countries and share similar social contexts as well as demographic transitions. I operated the Age-Period-Cohort Intrinsic Estimator model
to answer the questions using vital statistics and population census from the Statistics Bureau and the Ministry of Internal Affairs and Communications for Japan, and cause of death data and population census from Statistics Korea.

The results show that even though the two countries are neighbors that have had some similar socio-demographic contexts, the factors contributing to the increasing suicide rates vary in each country. Age effects are highest during the elderly period in South Korea, whereas age effects in Japan are highest during the fifties age bracket. Period effects in Japan increased sharply between 1995 and 2000, while period effects in South Korea mounted rapidly between 2000 and 2005. Cohort effects in Japan were highest among the 1905-1909 birth cohort and sustained a lower level since the 1925-1929 birth cohort, whereas the birth cohort born between 1915-1970 in South Korea showed high cohort effects.




This work made publicly available electronically on July 30, 2012.

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