Insights from parity status life tables for the 20th century U.S.

Parity status life table (PSLT) models show the implications of a set of age–parity-specific birth rates, and describe how women move through successive parities as they progress through their childbearing years. Here PSLT values for the U.S. are presented for the years 1917–1997 and for cohorts born 1902–1963. Cohort PSLTs show fertility levels similar to cohort TFRs, while period PSLTs generally track the conventional period TFR. Nonetheless, using rates specific to parity can increase the susceptibility of period rates to timing influences. Period PSLTs for the Baby Boom years show over 40% of women ultimately having 5 or more children, while cohort PSLTs show that no birth cohort ever had 30% of its members at those parities. The approximate regularity that has characterized the level of American fertility since the 1970s extends to patterns of children ever born as well. Two children are by far the most common family size, with about one-third of all women having that number. About one-sixth of all women ended childbearing at each of parities 0, 1, and 3. The remaining sixth of women have attained parity 4 or higher, with very few women having more than 6 children.