| Abstract: | Abstract An examination of the patterns of cohort fertility rates in a number of populations revealed the existence of a common pattern showing how mean family sizes of the different age-at-marriage groups of a given marriage cohort are built up over the reproductive span. Standard schedules of fertility patterns are generated by the use of the Gompertz function which defines the distribution of cumulative fertility rates of a given marriage cohort by marriage duration by means of only three parameters. The generated system is tested with the historical series for England and Wales and Sweden and is found adequate to describe widely different childbearing patterns. Some of the demographic implications of the existence of common fertility patterns are examined and the usefulness of the generated system in projecting future fertility trends is briefly discussed. |
