Barrett J C
Demography. 1978 Feb;15(1):87-98.
The effect of various factors on selection for family planning status and for natural fecundability is studied in a simulation that incorporates a beta distribution of fecundability among women. The mean fecundabilities of current spacers, current limiters, current nonusers, and pregnant women are compared. These ratios are influenced by duration of marriage and by desired number of children. Effects of different levels of contraception are measured. Another strategy, spacing the last two wanted births, is also studied. It is found that breast-feeding status has little effect on fecundability selection. The women usually found to have greatest fecundability are not those recently pregnant at durations of marriage five and ten years, unless they wanted fewer than two children, but rather those who are using contraception to limit the number of children.
在一个纳入了女性生育能力贝塔分布的模拟研究中，探讨了各种因素对计划生育状况选择和自然生育能力的影响。比较了当前采用间隔生育法者、当前采用限制生育法者、当前未使用者以及孕妇的平均生育能力。这些比率受婚姻持续时间和期望子女数量的影响。测定了不同避孕水平的效果。还研究了另一种策略，即对最后两个期望生育的孩子进行间隔生育。研究发现，母乳喂养状况对生育能力选择影响不大。通常被发现生育能力最强的女性并非那些在结婚五年和十年时近期怀孕的女性，除非她们想要的孩子少于两个，而是那些正在使用避孕措施来限制子女数量的女性。
