This paper analyzes the long-term effects of potentially avoidable  C-sections on children's health. Using Finnish administrative data, we document that physicians perform more unplanned C-sections during their regular working hours on days that precede a weekend or public holiday and use this exogenous variation as an instrument for C-sections. We supplement our instrumental variables results with a differences-in-differences estimation that exploits variation in birth mode within sibling pairs and across families. Our results suggest that avoidable unplanned C-sections increase the risk of asthma, but do not affect other immune-mediated disorders previously associated with C-sections.

• Media coverage: La Vanguardia, El Periódico, Yle. Watch us explain this paper and more of our research on C-sections here (in Spanish)

Although there is a large gap between Black and White American life expectancies, the gap fell 48.9% between 1990-2018, mainly due to mortality declines among Black Americans. We examine age-specific mortality trends and racial gaps in life expectancy in rich and poor U.S. areas and with reference to six European countries. Inequalities in life expectancy are starker in the U.S. than in Europe. In 1990 White Americans and Europeans in rich areas had similar overall life expectancy, while life expectancy for White Americans in poor areas was lower. But since then even rich White Americans have lost ground relative to Europeans. Meanwhile, the gap in life expectancy between Black Americans and Europeans decreased by 8.3%. Black life expectancy increased more than White life expectancy in all U.S. areas, but improvements in poorer areas had the greatest impact on the racial life expectancy gap. The causes that contributed the most to Black mortality reductions included: Cancer, homicide, HIV, and causes originating in the fetal or infant period. Life expectancy for both Black and White Americans plateaued or slightly declined after 2012, but this stalling was most evident among Black Americans even prior to the COVID-19 pandemic. If improvements had continued at the 1990-2012 rate, the racial gap in life expectancy would have closed by 2036. European life expectancy also stalled after 2014. Still, the comparison with Europe suggests that mortality rates of both Black and White Americans could fall much further across all ages and in both rich and poor areas.

• Media coverage: The Atlantic, The Guardian, Inequality.org

We analyse the evolution of mortality rates in Spain by age and gender between 1990 and 2018. We compare municipalities, ranked by socio-economic status (SES) and grouped into bins of similar population size, to study changes not only in levels but also in inequality in mortality across the SES spectrum. We document large decreases in mortality rates throughout the period for all age groups, including children, even after 2000, and continuing after the Great Recession. These declines are stronger for boys and men, who had higher mortality rates to begin with. We find that inequality in mortality across municipalities was low among the young by 2018, while it was higher among adult men and older women. Inequality in fact increased over the period for older men. We explore the role of different causes of death and find that this increase in inequality is driven by stronger improvements in cancer-related mortality among men living in richer areas. These improvements are not found among women, given their increases in mortality due to lung cancer.

Cesarean sections have been associated in the literature with poorer newborn health, particularly with a higher incidence of respiratory morbidity. Most studies suffer, however, from potential omitted variable bias, as they are based on simple comparisons of mothers who give birth vaginally and those who give birth by cesarean section. We try to overcome this limitation and provide credible causal evidence by using variation in the probability of having a c-section that is arguably unrelated to maternal and fetal characteristics: variation by time of day. Previous literature documents that, while nature distributes births and associated problems uniformly, time-dependent variables related to physicians’ demand for leisure are significant predictors of unplanned c-sections. Using a sample of public hospitals in Spain, we show that the rate of c-sections is higher during the early hours of the night compared to the rest of the day, while mothers giving birth at the different times are similar in observable characteristics. This exogenous variation provides us with a new instrument for type of birth: time of delivery. Our results suggest that non-medically indicated c-sections have a negative and significant impact on newborn health, as measured by Apgar Scores, but that the effect is not severe enough to translate into more extreme outcomes. 

• Media coverage: La Vanguardia, El Periódico, ABC. Read our blog posts in The Barcelona GSE Voice and in Nada es Gratis, or watch us explain our findings here (in Spanish) or here (in English)

• Awarded second prize of 2018 iHEA Annual Student Paper Prize. Nominated for the 2019 La Vanguardia Science award

What is the impact of the oral contraceptive pill on the mental health of adolescent girls? Using administrative data from Denmark and exploiting the variation in the timing of pill initiation in an event study design, we find that the likelihood of a depression diagnosis and antidepressant use increases shortly after pill initiation. We then uncover substantial variation in primary care providers’ tendency to prescribe the pill to adolescents, unrelated to patient characteristics. Being assigned to a high prescribing physician strongly predicts pill use by age 16 and leads to worse mental health outcomes between ages 16-18.

• Read our related VoxEU column 

Men’s historical advantage in educational attainment has recently been reversed in many countries. I study the implications for family formation of the new female advantage in education in the marriage market, exploiting a Finnish school reform that increased women’s relative level of education. I analyze the reduced-form relationship between marriage market exposure to the reform and family outcomes. I find decreases in marriage and fertility in marriage markets with a larger female educational advantage. These results are mostly driven by the increasing mismatch between the educational distributions of men and women, and might have negative consequences for low-educated men’s mental health.