In the post-Recession era, U.S. fertility rates have continued to fall. It is unclear if these declines are driven by shifts in fertility goals or growing difficulty in achieving goals. In this paper, we construct synthetic cohorts of men and women to examine both cross-cohort and within-cohort changes in fertility goals using multiple cycles of the National Survey of Family Growth. Although more recent cohorts exhibit lower achieved fertility at younger ages than earlier cohorts at the same age, intended parity remains around two children, and intentions to remain childless rarely exceed 15 percent. There is weak evidence of a growing fertility gap in the early 30s, suggesting more recent cohorts will need considerable childbearing in the 30s and early 40s to “catch up” to earlier goals, yet low-parity women in their early 40s are decreasingly likely to have unfulfilled fertility desires or intentions to have children. Low-parity men in their early 40s, though, are increasingly likely to intend children. Declines in U.S. fertility thus seem to be largely driven not by changes in early-life fertility goals so much as either a decreasing likelihood of achieving earlier goals or, perhaps, shifts in the preferred timing of fertility that depress period measures.

中文翻译：

---

当前美国生育群体不断变化的生育目标和行为

在后经济衰退时代，美国生育率持续下降。目前尚不清楚这些下降是否是由生育目标的变化或实现目标的难度加大造成的。在本文中，我们构建了男性和女性的综合队列，利用全国家庭成长调查的多个周期来检查生育目标的跨队列和队列内变化。尽管最近的队列在较年轻时表现出比早期同龄队列的生育率更低，但预期均等仍维持在两个孩子左右，并且不生育的意愿很少超过 15%。有微弱的证据表明，30 岁出头的生育率差距正在扩大，这表明最近的一代人需要在 30 岁和 40 岁出头进行大量生育才能“赶上”早期的目标，然而，40岁出头的低生育率女性未实现生育愿望或生孩子意图的可能性降低。然而，40岁出头的低生育率男性越来越有可能想要孩子。因此，美国生育率下降的主要原因似乎不是早期生育目标的变化，而是实现早期目标的可能性降低，或者可能是首选生育时间的变化，从而抑制了经期指标。