Bongaarts J
Popul Stud (Camb). 1999 Nov;53(3):277-89. doi: 10.1080/00324720308088.
This study examines the role of tempo effects in the fertility declines of less developed countries. These effects temporarily inflate the total fertility of a population during periods when the age at childbearing declines and deflate it when childbearing is postponed. An analysis of data from the World Fertility Surveys and the Demographic and Health Surveys demonstrates that fertility trends observed in many less developed countries are likely to be distorted by changes in the timing of childbearing. In most countries women are delaying childbearing, which implies that observed fertility is lower than it would have been without tempo changes. This pattern is most clearly documented in Taiwan, where accurate birth statistics from a vital registration system make it possible to estimate the tempo components of fertility annually from 1978 to 1993. The small but unexpected rise in the total fertility of Colombia in the early 1990s is attributed to a decline in the negative tempo distortion that prevailed in the 1980s. Similar interruptions of ongoing fertility declines may occur in the future in other countries when existing negative tempo effects are removed.
本研究探讨了生育节奏效应在欠发达国家生育率下降过程中所起的作用。这些效应在生育年龄下降期间会暂时抬高人口的总和生育率，而在生育推迟时则会使其降低。对世界生育率调查以及人口与健康调查数据的分析表明，许多欠发达国家所观察到的生育率趋势很可能因生育时间的变化而受到扭曲。在大多数国家，女性生育正在推迟，这意味着所观察到的生育率低于若无生育节奏变化时的水平。这种模式在台湾有最为清晰的记录，那里完善的出生登记系统所提供的准确出生统计数据使得从1978年至1993年每年都能够估算出生育率的节奏构成部分。20世纪90年代初哥伦比亚总和生育率出现的虽小但出人意料的上升，归因于20世纪80年代盛行的负向生育节奏扭曲现象有所减少。当现有的负向生育节奏效应消除时，未来其他国家也可能出现类似的正在进行的生育率下降中断情况。
