Griffen Andrew S
Economics Research Building, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Econ Hum Biol. 2016 Mar;20:55-69. doi: 10.1016/j.ehb.2015.10.004. Epub 2015 Nov 9.
This paper estimates a height production function using data from a randomized nutrition intervention conducted in rural Guatemala from 1969 to 1977. Using the experimental intervention as an instrument, the IV estimates of the effect of calories on height are an order of magnitude larger than the OLS estimates. Information from a unique measurement error process in the calorie data, counterfactuals results from the estimated model and external evidence from migration studies suggest that IV is not identifying a policy relevant average marginal impact of calories on height. The preferred, attenuation bias corrected OLS estimates from the height production function suggest that, averaging over ages, a 100 calorie increase in average daily calorie intake over the course of a year would increase height by 0.06 cm. Counterfactuals from the model imply that calories gaps in early childhood can explain at most 16% of the height gap between Guatemalan children and the US born children of Guatemalan immigrants.
本文利用1969年至1977年在危地马拉农村进行的一项随机营养干预的数据,估计了一个身高生产函数。将实验性干预作为一种工具变量,卡路里对身高影响的工具变量估计值比普通最小二乘法(OLS)估计值大一个数量级。来自卡路里数据中独特测量误差过程的信息、估计模型的反事实结果以及移民研究的外部证据表明,工具变量并没有识别出卡路里对身高的与政策相关的平均边际影响。身高生产函数中经过衰减偏差校正的首选普通最小二乘法估计值表明,平均而言,在一年的时间里,平均每日卡路里摄入量增加100卡路里,身高将增加0.06厘米。该模型的反事实结果表明,幼儿期的卡路里差距最多只能解释危地马拉儿童与危地马拉移民在美国出生的子女之间身高差距的16%。