Division of Health Policy and Administration, School of Public Health, Yale University, New Haven, CT, USA.
Health Econ. 2011 Nov;20(11):1349-61. doi: 10.1002/hec.1675. Epub 2010 Oct 18.
This paper re-examines the effects of breastfeeding on long-term educational outcomes using longitudinal data on siblings. While family-fixed effects allow controls for all shared family factors, these estimators are sensitive to compensating or reinforcing behaviors by parents. These biases may be particularly important for estimating the effects of parental investment such as breast feeding, where sibling discordance may be difficult to treat as a random outcome and may result in persistence in differential investments between siblings. This paper uses a unique question asked to adolescent siblings about parental favoritism to adjust for potential reinforcing behavior by parents. Standard fixed effects estimates suggest important long-term educational effects of breastfeeding; however, these effects are uniformly eliminated after focusing on families who treat siblings equally. These findings shed light on the mechanisms linking associations between breastfeeding and longer term outcomes.
本文利用兄弟姐妹的纵向数据，重新考察了母乳喂养对长期教育成果的影响。虽然家庭固定效应允许控制所有共同的家庭因素，但这些估计对父母的补偿或强化行为很敏感。这些偏差对于估计父母投资（如母乳喂养）的影响可能尤为重要，因为兄弟姐妹之间的不和谐可能难以视为随机结果，并且可能导致兄弟姐妹之间的投资差异持续存在。本文利用一个独特的问题，询问青少年兄弟姐妹关于父母偏心的问题，以调整父母潜在的强化行为。标准固定效应估计表明母乳喂养有重要的长期教育效果；然而，在关注平等对待兄弟姐妹的家庭后，这些影响都被统一消除了。这些发现为母乳喂养与更长期结果之间的关联机制提供了线索。
