The effects of maternal fasting during Ramadan on birth and adult outcomes

We use the Islamic holy month of Ramadan as a natural experiment for evaluating the short and long-term effects of fasting during pregnancy. Using Michigan natality data we show that in utero exposure to Ramadan among Arab births results in lower birthweight and reduced gestation length. Preconception exposure to Ramadan is also associated with fewer male births. Using Census data in Uganda we also find that Muslims who were born nine months after Ramadan are 22 percent (p =0.02) more likely to be disabled as adults. Effects are found for vision, hearing, and especially for mental (or learning) disabilities. This may reflect the persistent effect of disruptions to early fetal development. We find no evidence that negative selection in conceptions during Ramadan accounts for our results. Nevertheless, caution in interpreting these results is warranted until our findings are corroborated in other settings. ; Not for Citation.Prenatal care ; Ramadan ; Fasting (Islam)

Capital, wages and growth: Theory and evidence

Returns to scale to capital and the strength of capital externalities play a key role for the empirical predictions and policy implications of different growth theories. We show that both can be identified with individual wage data and implement our approach at the city-level using US Census data on individuals in 173 cities for 1970, 1980, and 1990. Estimation takes into account fixed effects, endogeneity of capital accumulation, and measurement error. We find no evidence for human or physical capital externalities and decreasing aggregate returns to capital. Returns to scale to physical and human capital are around 80 percent. We also find strong complementarities between human capital and labor and substantial total employment externalities.Returns to scale to capital, human capital, capital externalities, complementarities, scale effects, cities

Fasting During Pregnancy and Children's Academic Performance

We consider the effects of daytime fasting by pregnant women during the lunar month of Ramadan on their children's test scores at age seven. Using English register data, we find that scores are .05 to .08 standard deviations lower for Pakistani and Bangladeshi students exposed to Ramadan in early pregnancy. These estimates are downward biased to the extent that Ramadan is not universally observed. We conclude that the effects of prenatal investments on test scores are comparable to many conventional educational interventions but are likely to be more cost effective and less subject to "fade out".educational outcomes, pregnancy, fasting

Fasting During Pregnancy and Children's Academic Performance

We consider the effects of daytime fasting by pregnant women during the lunar month of Ramadan on their children's test scores at age seven. Using English register data, we find that scores are .05 to .08 standard deviations lower for Pakistani and Bangladeshi students exposed to Ramadan in early pregnancy. These estimates are downward biased to the extent that Ramadan is not universally observed. We conclude that the effects of prenatal investments on test scores are comparable to many conventional educational interventions but are likely to be more cost effective and less subject to "fade out".

The Costs of Low Birth Weight

Birth weight has emerged as the leading indicator of infant health and welfare and the central focus of infant health policy. This is because low birth weight (LBW) infants experience severe health and developmental difficulties that can impose enormous costs on society. But would the prevention of LBW generate equally sizable cost savings and health improvements? Estimates of the return to LBW-prevention from cross-sectional associations may be biased by omitted variables that cannot be influenced by policy, such as genetic factors. To address this, we compare the hospital costs, health at birth, and infant mortality rates between heavier and lighter infants from all twin pairs born in the United States. We also examine the effect of maternal smoking during pregnancy the leading risk factor for LBW in the United States on health among singleton births after controlling for detailed background characteristics. Both analyses imply substantially smaller effects of LBW than previously thought, suggesting two possibilities: 1) existing estimates overstate the true costs and consequences of LBW by at least a factor of four and by as much as a factor of 20; or 2) different LBW-preventing interventions have different health and cost consequences, implying that policy efforts that presume a single return to reducing LBW will necessarily be suboptimal.

Perinatal Health Among 1 Million American-Born Chinese

Son preference is well documented in many Asian counties. Sex selection generates sex ratios (# of males/# of females) above the biologically normal ratio of around 1.05 at birth. For China, Chen, Li, and Meng [2013] argue that availability of prenatal sex determination through ultrasound lead to a 40-50% increase in the sex imbalance during the 1980s. Son preference manifests in sibling sex composition, where the sex ratio of firstborn children is relatively normal but rises at higher birth orders in the absence of a previous son [Yi et al., 1993]. Because official birth certificate and hospital discharge microdata are not publicly available for China, most studies analyze population census data. This tends to focus empirical work on the sex imbalance itself. A key unanswered question is the effect of gender preference on “survivors”. An exception is Li and Wu [2011], who use the China Health and Nutrition Survey to show that mother’s nutrition may deteriorate postpartum upon having a daughter relative to a son. Gender preference aside, perinatal health has a profound impact on population health. The WHO defines the perinatal period as running from 22 weeks gestation to 7 days after birth. Over half of infant deaths occur within first 7 days of life. The death rate for children under age one is more than 13 times higher than the death rate for children age 15 to 19, the group with the next highest rate. Moreover, the fetal origins hypothesis suggests that small gaps in perinatal health can map to large later-life gaps. In the absence of data for China, we explore the perinatal health of American-born Chinese (1.2% of US population)

Human Capital Development Before Age Five

This chapter seeks to set out what Economists have learned about the effects of early childhood influences on later life outcomes, and about ameliorating the effects of negative influences. We begin with a brief overview of the theory which illustrates that evidence of a causal relationship between a shock in early childhood and a future outcome says little about whether the relationship in question biological or immutable. We then survey recent work which shows that events before five years old can have large long term impacts on adult outcomes. Child and family characteristics measured at school entry do as much to explain future outcomes as factors that labor economists have more traditionally focused on, such as years of education. Yet while children can be permanently damaged at this age, an important message is that the damage can often be remediated. We provide a brief overview of evidence regarding the effectiveness of different types of policies to provide remediation. We conclude with a list of some of (the many) outstanding questions for future research. Hard-copy subscribers may access the tables for this paper here .

Health Capital and the Prenatal Environment: The Effect of Maternal Fasting During Pregnancy

We use the Islamic holy month of Ramadan as a natural experiment in fasting and fetal health. In Michigan births 1989-2006, we find prenatal exposure to Ramadan among Arab mothers results in lower birthweight and reduced gestation length. Exposure to Ramadan in the first month of gestation is also associated with a sizable reduction in the number of male births. In Census data for Uganda, Iraq, and the US we find strong associations between in utero exposure to Ramadan and the likelihood of being disabled as an adult. Effects are particularly large for mental (or learning) disabilities. We also find significant effects on proxies for wealth, earnings, the sex composition of the adult population, and more suggestive evidence of effects on schooling. We find no evidence that negative selection in conceptions during Ramadan accounts for our findings, suggesting that avoiding Ramadan exposure during pregnancy is costly or the long-term effects of fasting unknown.

Chernobyl's subclinical legacy: prenatal exposure to radioactive fallout and school outcomes in Sweden

Japanese atomic bomb survivors irradiated 8-25 weeks after ovulation subsequently suffered reduced IQ [Otake and Schull, 1998]. Whether these findings generalize to low doses (less than 10 mGy) has not been established. This paper exploits the natural experiment generated by the Chernobyl nuclear accident in April 1986, which caused a spike in radiation levels in Sweden. In a comprehensive data set of 562,637 Swedes born 1983-1988, we find the cohort in utero during the Chernobyl accident had worse school outcomes than adjacent birth cohorts, and this deterioration was largest for those exposed approximately 8-25 weeks post conception. Moreover, we find larger damage among students born in regions that received more fallout: students from the eight most affected municipalities were 3.6 percentage points less likely to qualify to high school as a result of the fallout. Our findings suggest that fetal exposure to ionizing radiation damages cognitive ability at radiation levels previously considered safe