Morgan S P
Demography. 1981 Aug;18(3):267-85.
While births may be dichotomous, fertility intentions are not inherently so. Intentions are predictions about the future and, as such, are couched in considerable uncertainty. Ignoring this uncertainty hides much of what could be learned from data on fertility intentions. This paper presents a model which allows analysis of the full range of intentions. This paper presents a model which allows analysis of the full range of intentions. After selecting a sample of women in the later stage of childbearing (e.g., those who intend fewer than two additional children) from the 1965 and 1970 National Fertility Studies, it is shown that: (1) substantial portions of women at this stage of the reproductive life cycle were indeed uncertain of their parity-specific intention; (2) this certainty, like more firm intentions, varies by age and parity as the model predicts; and (3) there were significant shifts in the level of certainty between 1965 and 1970. Specifically, while intentions for third, fourth, and fifth births declined, more women "didn't know" if they intended to have another child or not. Among those not intending another child, more seemed uncertain of this intention in 1970 than did comparable women in 1965. In contrast, those intending another child seemed more certain. These changes in intention and uncertainty indicate that the observed decline in intended parity was tentative. Post-1970 evidence suggests that this tentative decline has become an equivocal one.
虽然生育可能是二元的,但生育意愿并非天生如此。意愿是对未来的预测,因此存在相当大的不确定性。忽视这种不确定性会掩盖许多可以从生育意愿数据中学到的东西。本文提出了一个模型,该模型允许对整个意愿范围进行分析。在从1965年和1970年的全国生育研究中选取处于生育后期的女性样本(例如,那些打算再生育少于两个孩子的女性)后,结果表明:(1)处于生殖生命周期这一阶段的很大一部分女性确实对她们特定胎次的意愿不确定;(2)这种确定性,如同更坚定的意愿一样,如模型所预测的那样随年龄和胎次而变化;(3)1965年至1970年间确定性水平发生了显著变化。具体而言,虽然第三、第四和第五胎的生育意愿下降,但更多女性“不知道”自己是否打算再要一个孩子。在那些不打算再要孩子的人中,1970年比1965年的可比女性似乎对这种意愿更不确定。相比之下,那些打算再要一个孩子的人似乎更确定。意愿和不确定性的这些变化表明,观察到的预期胎次下降是暂时的。1970年后的证据表明,这种暂时下降已变得模棱两可。