Re-estimating per Capita Individual Consumption by Age from Household Data

Mori and Inaba proposed an estimation method of deriving individual consumption by age from macro data classified by age of household head (HH), using quadratic programming, 1997. We replaced their approach by regression with weights which are determined by the magnitude of standardized residuals, following the leads of Huber, 1981 and Minotani, 1992. Using our revised method which provides objective statistics, the estimates of per capita individual consumption of fresh fruit and fresh fish, respectively, by non-adults are substantially larger and those for the young adults somewhat smaller in our studies than in previous studies. It seems quite apparent that Japanese children and young adults have decreased their at-home consumption of these products substantially in recent years. Those older than 50years of age seem to have maintained their consumption at relatively high levels.