Haughton D, Haughton J
Department of Mathematical Sciences, Bentley College, Waltham, Massachusetts, USA.
J Biosoc Sci. 1996 Jul;28(3):355-65. doi: 10.1017/s0021932000022422.
Son preference is strong in Vietnam, according to attitudinal surveys and studies of contraceptive prevalence and birth hazards. These techniques assume a single model is valid for all families, but it is more plausible that son preference is found for some, but not all, families. Heterogeneous preferences may be addressed with a mixture model. This paper specifies and estimates a two-Weibull regression model, applied to the interval between the second and third births. The data come from the Vietnam Living Standards Survey of 1992-93. Applying information criteria, graphs, and martingale-based residuals, the two-Weibull model is found to fit better than a one-Weibull model. Roughly half of parents have son preference and, curiously, a propensity for fewer children. The other group has more children, no son preference, and is colourless in the sense that the birth interval is difficult to predict on the basis of the regressors used.
根据态度调查以及对避孕普及率和生育风险的研究，越南存在强烈的男孩偏好。这些技术假定单一模型对所有家庭都有效，但更合理的情况可能是，某些家庭存在男孩偏好，而不是所有家庭。异质性偏好可以用混合模型来处理。本文设定并估计了一个双威布尔回归模型，应用于第二胎和第三胎之间的间隔。数据来自1992 - 1993年的越南生活水平调查。通过应用信息准则、图表和基于鞅的残差，发现双威布尔模型比单威布尔模型拟合得更好。大约一半的父母有男孩偏好，奇怪的是，他们倾向于生育较少的孩子。另一组生育的孩子更多，没有男孩偏好，并且从基于回归变量难以预测生育间隔的意义上来说是无明显特征的。
