A Cohort Analysis of Equity Shares in Japanese Household Financial Assets

Aggregate data on equity shares in Japanese household financial assets, classified by period and age, are decomposed into age, period, and cohort effects by using two different identification methods: one assumes that each effect fluctuates smoothly and the other assumes that the period effect is orthogonal to a linear time trend. Both methods provide a very similar and striking empirical finding. The main factor in the life-cycle movement of equity shares is not the age effect but the cohort effect. Comprehensive robustness checks support this finding.