我的父母:累积饥荒经历代际影响的疤痕效应与选择效应

The Scarring and Selection Effects of Parents’ Cumulative Risk of Famine Exposure on their Children’s Height

利用饥荒作为自然实验,本文探讨父母早年饥荒经历的累积风险对其子女身高代际影响的疤痕效应与选择效应。运用中国预防科学医学院和美国北卡罗来纳大学人口中心合作完成的中国健康与营养调查(China Health and Nutrition Survey,CHNS)数据,利用个体累积风险与出生队列的差异构建双重差分模型(DID),本文发现,母亲的累积饥荒风险对其子女身高既有疤痕效应,也有选择效应,但选择效应大于疤痕效应。该结果意味着,母亲饥荒经历的累积严重程度越高,子女的身高越高。在排除了男孩偏好、选型婚配(assortative mating)等作用渠道后,本文认为,累积饥荒风险通过影响父母的身高而部分作用于子女的身高。本文传递给发展中国家的信息是,发展中的挫折可能使得我们未来变得更加强大。

Treating the 1959—1961 Chinese Great Famine as a natural experiment,this paper explores the scarring and selection effects of parents’ cumulative risk of early-stage famine exposure on their children’s height.In this paper,the parents’ year and place of birth determine their cumulative risk of exposure to famine.We divided the parents into three cohorts,namely,those who experienced famine in early childhood(born 1956.01—1958.12,hereinafter referred to as the “ old famine cohort”),those who experienced famine during an embryonic stage or during infancy(born 1959.01—1962.09,hereinafter referred to as the “ young famine cohort”),and those who did not experience famine(born between 1954.01—1955.12 and 1962.10—1967.12).Treating the parents who did not experience famine as the control group,we constructed a Difference-in-Difference( DID) model using the differences in the individual cumulative risk and the birth cohorts.Based on data from the China Health and Nutrition Survey( CHNS),we find that the mothers’ cumulative risk of famine exposure had both a scarring effect and a selection effect on the height of their children,but the selection effect was greater than the scarring effect.The results imply that the higher the mothers’ cumulative risk of exposure to famine,the higher the height of their children.Specifically,for the children of the old famine cohort,the scarring effect reduced the height of boys(girls) by 7.263(7.481)cm,and the selection effect increased the height of boys(girls) by 7.563(7.790) cm.The net gain in height for boys(girls) was approximately 0.300(0.309) cm.For the children of the young famine cohort,the scarring effect reduced the height of boys(girls)by 10.343(10.748) cm,and the selection effect increased the height of boys(girls) by 10.514(10.926) cm.The net gain in height for boys(girls) was approximately 0.171(0.178) cm.However,the fathers’ cumulative risk of famine exposure had no significant scarring or selection effects.The results of this paper are relatively robust.After excluding male preference,marriage selection,and matchmaking,we argue that the cumulative famine risk partly affects the height of children by affecting the height of their parents.The message to developing countries is that setbacks in development may make them stronger in the future.