Wachter K W, Lee R D
Graduate Group in Demography, University of California, Berkeley 94720.
Demography. 1989 Feb;26(1):99-115.
Lee's (1974) formal demographic feedback models summarize the implications for births and age-structure of neo-Malthusian theories of baby booms such as those of Easterlin. For some parameter values, such models imply sustained cycles, so-called "limit cycles", in births. Frauenthal and Swick recently reestimated a continuous-age version of Lee's basic cohort model with U.S. series and, contrary to Lee's original findings, concluded that "limit cycles oscillations have been occurring in U.S. births." This article disputes their conclusion, ascribing it to an inconsistency in detrending procedures. Furthermore, it corrects Lee's original conclusion by showing that his alternative period labor-force feedback model, estimated from U.S. series, leads to cycles of implausibly long period. This article thus reopens the question of whether any feedback model could account for the observed cycles in U.S. births.
李（1974年）的正式人口统计学反馈模型总结了诸如伊斯特林等人的新马尔萨斯主义婴儿潮理论对出生和年龄结构的影响。对于某些参数值，此类模型意味着出生人数会出现持续的周期，即所谓的“极限环”。弗劳恩索尔和斯威克最近用美国的数据序列重新估计了李的基本队列模型的连续年龄版本，与李最初的研究结果相反，他们得出结论称“美国的出生人数一直在出现极限环振荡”。本文对他们的结论提出质疑，认为这是去趋势化过程中的不一致导致的。此外，本文纠正了李最初的结论，指出从美国数据序列估计出的他的另一种周期性劳动力反馈模型会导致周期长得难以置信。因此，本文重新提出了一个问题，即是否有任何反馈模型能够解释美国出生人数中观察到的周期现象。
