Happiness in Japan: A Hierarchical Age-Period-Cohort Analysis Based on JGSS Cumulative Data 2000–2015

The purpose of this paper is to examine factors affecting the happiness of Japanese people based on the JGSS cumulative data 2000–2015. JGSS is a repeated cross-sectional survey conducted once a year or every other years. Analyzing the pooled data of JGSS makes it possible to examine the cohort effect and period effect. In addition, we can achieve more generalized findings by examining the effect of variables at the individual level while controlling for the effect of cohorts and periods. We employed a hierarchical Age-Period-Cohort Analysis because individuals are nested within two social contexts: period (time points of surveys) and cohort (birth cohorts with 5-year interval). The period and the cohort were set at the group level, age and other independent variables predicting happiness were set at the individual level. The results of our analysis revealed that (1) the age effect followed a U-shaped curve, (2) happiness declined in 2003, (3) happiness was low in 1935–1939 birth cohort, (4) original social stratum and social opportunities in the early period of life affected happiness over the life course, (5) subjective relative household income had a stronger relation with happiness than equivalent household income, (6) working status and marital status have a different effect on happiness between men and women.