Prolificacy distribution of white wives according to fertility tables for the registration area
Whelpton, P.K.; Jackson, N.E.
Human Biology 12(1): 35-58
1940
ISSN/ISBN: 0018-7143 DOI: 10.2307/41447439Document Number: 393687
Corrections in method and adjustments of basic data are suggested for computing the prolificacy distribution of white wives in a cohort exposed continually to specific birth, death, marriage, divorce and widowhood rates of a base period. Allowing for incomplete birth registration, distributing illegitimate births by estimated order of birth instead of assuming all to be first births, partially adjusting births for misstatements of legitimacy and order, using the marital distribution of the Birth Registration Area instead of the U. S., and using the 3-yr. period 1919-21 (or 7-yr. period 1917-23) instead of the somewhat abnormal single year 1919, changes the % of wives childless and fertile from 17.8 and 82.2 respectively as computed by Lotka to 12 and 88. For wives with unbroken marriages the change in percentages is from 12.6 and 87.4 to 6.9 and 93.1. An original method is described for computing corresponding percentages for wives marrying under age 45, the 1919-21 percentages being 10.3 and 89.7 for all such wives and 5.1 and 94.9 for those with unbroken marriages. The prolificacy distribution of white wives according to 1929-31 rates is contrasted with that according to 1919-21 rates, the % infertile increasing greatly, the % with 1 or 2 births changing but little, and the % with 3 or more births decreasing, the extent of the decrease varying directly and greatly with the number of births. The limitations of prolificacy distribution tables are discussed, particularly the effect of birth rates in yrs. prior to a base period, of long time changes in the extent and effectiveness of contraceptive practices, and of factors like depression and war which may make the base period abnormal.