[An analysis of recent fertility decline in Japan (author's transl)].

Over the past several years, Japanese fertility has begun to decline. The author analyzes this recent fertility trend statistically. In part 1 where he covers a general view of fertility, basic fertility measures are examined. The number of births by age of mother are analyzed by the number of the female population according to their ages and fertility. Various indicators of fertility such as crude birth, standardized birth rate, total fertility rate, age-specific birth rate, and age-birth order-specific birth rates are examined. In part 2 where there is a discussion of marriage and marital fertility, the number of marriages and marriage rates by age are examined. For marriage rate, age-specific marriage rates of female population who are not married currently are estimated. Except for the census-taking years, marital status data are not available. Therefore, the estimation of population not currently married is required for the marital status life tables. Also analyzed are the proportion married by age and age-specific marital fertility. In part 3, cohort fertility is examined in light of the number of children ever born and accumulated by age-specific fertilities for cohorts from vital statistics. It is clear that cohort fertility has not changed much as period fertility in recent years. The noticeable change in cohort fertility is seen as a shift to an older age for childbearing. (author's modified)