Orsini Chiara, Avendano Mauricio
London School of Economics and Political Science, Cowdray House, Houghton Street, London, WC2A 2AE, United Kingdom.
London School of Economics and Political Science, Cowdray House, Houghton Street, London, WC2A 2AE, United Kingdom; Harvard School of Public Health, Department of Social and Behavioural Sciences, 677 Huntington Avenue, Boston, Massachusetts 02115, United States of America.
PLoS One. 2015 May 14;10(5):e0123501. doi: 10.1371/journal.pone.0123501. eCollection 2015.
We study whether the relationship between the state unemployment rate at the time of conception and infant health, infant mortality and maternal characteristics in the United States has changed over the years 1980-2004. We use microdata on births and deaths for years 1980-2004 and find that the relationship between the state unemployment rate at the time of conception and infant mortality and birthweight changes over time and is stronger for blacks than whites. For years 1980-1989 increases in the state unemployment rate are associated with a decline in infant mortality among blacks, an effect driven by mortality from gestational development and birth weight, and complications of placenta while in utero. In contrast, state economic conditions are unrelated to black infant mortality in years 1990-2004 and white infant mortality in any period, although effects vary by cause of death. We explore potential mechanisms for our findings and, including mothers younger than 18 in the analysis, uncover evidence of age-related maternal selection in response to the business cycle. In particular, in years 1980-1989 an increase in the unemployment rate at the time of conception is associated with fewer babies born to young mothers. The magnitude and direction of the relationship between business cycles and infant mortality differs by race and period. Age-related selection into motherhood in response to the business cycle is a possible explanation for this changing relationship.
我们研究了1980年至2004年期间，美国怀孕时的州失业率与婴儿健康、婴儿死亡率及母亲特征之间的关系是否发生了变化。我们使用了1980年至2004年的出生和死亡微观数据，发现怀孕时的州失业率与婴儿死亡率及出生体重之间的关系随时间变化，且对黑人的影响比对白人更强。在1980年至1989年期间，州失业率的上升与黑人婴儿死亡率的下降相关，这一效应由妊娠发育和出生体重导致的死亡率以及子宫内胎盘并发症所驱动。相比之下，1990年至2004年期间，州经济状况与黑人婴儿死亡率无关，且在任何时期与白人婴儿死亡率均无关，尽管不同死因的影响有所不同。我们探究了这些研究结果的潜在机制，包括在分析中纳入年龄小于18岁的母亲，发现了与年龄相关的母亲因应商业周期而进行自我选择的证据。特别是在1980年至1989年期间，怀孕时失业率的上升与年轻母亲生育的婴儿数量减少有关。商业周期与婴儿死亡率之间关系的强度和方向因种族和时期而异。因应商业周期而进行的与年龄相关的生育选择可能是这种变化关系的一个解释。
