Bhashkar Mazumder

Intergenerational Economic Mobility in the United States, 1940 to 2000

We estimate trends in intergenerational economic mobility by matching men in the Census to synthetic parents in the prior generation. We find that mobility increased from 1950 to 1980 but has declined sharply since 1980. While our estimator places greater weight on location effects than the standard intergenerational coefficient, the size of the bias appears to be small. Our preferred results suggest that earnings are regressing to the mean more slowly now than at any time since World War II, causing economic differences between families to become more persistent. However, current rates of positional mobility appear historically normal.

The 1918 influenza pandemic and subsequent health outcomes : An analysis of SIPP data

The fetal-origins hypothesis has recently achieved “textbook” status in medicine (see Colin D. Rudolph and Abraham M. Rudolph, 2003; David A. Warrell et al., 2003) and is drawing increasing attention from social scientists (e.g., Anne Case et al., 2005; Janet Currie and Enrico Moretti, 2005). The hypothesis holds that disruptions to fetal nutrition can exert persistent effects on subsequent health. From the perspective of a health production function, determinants of health may be divided into (i) post-birth health investments (e.g., Medicare) and (ii) the initial health endowment. The fetalorigins hypothesis emphasizes the importance of the initial health endowment, often proxied with birth weight, in determining adult health. Despite growing acceptance of the fetal-origins hypothesis by physicians and epidemiologists, the physiologic mechanisms by which fetal damage exerts long-term effects are relatively poorly understood. Experimental evidence from animal studies has established that maternal nutrition has a causal effect on subsequent health. Still, researchers have questioned the causality of statistical associations drawn from human populationbased studies of size at birth and subsequent health (e.g., Kathleen M. Rasmussen, 2001). A particular concern is whether omitted factors might bias or even account for the positive correlations between measures of early-life and adult health. Recent research has used the 1918 Influenza Pandemic as a natural experiment for studying the effects of fetal health (Almond, 2003). In contrast to typical influenza strains, the 1918 virus disproportionately affected young adults: approximately one-third of pregnant women contracted the debilitating virus. The Pandemic arrived without warning and was highly concentrated between October 1918 and January 1919. As a result, the long-term damage predicted by the fetal-origins hypothesis is similarly concentrated. Approximately two-thirds of those in utero during the height of the Pandemic would have been born in the first six months of 1919. In order to bias estimates of long-term fetal effects, post-birth health investments would have to behave in the same abrupt manner as the Pandemic. Using Decennial Census data for 1960–1980, Almond (2003) found that cohorts in utero during the height of the Pandemic displayed reduced educational attainment, increased rates of disability, lower income, and lower socioeconomic status. However, the absence of specific health outcomes in the Census precludes identification of physiologic pathways and therefore limits the relevance of the findings for physicians and epidemiologists. Using data from the Survey of Income and Program Participation (SIPP), this study finds that cohorts in utero during the Pandemic exhibit impaired health outcomes relative to cohorts born a few months earlier or later. That these patterns are manifest 65–80 years after the Pandemic suggests that changes to fetal health can have life-long effects.

Lingering prenatal effects of the 1918 influenza pandemic on cardiovascular disease

Prenatal exposure to the 1918 influenza pandemic (Influenza A, H1N1 subtype) is associated with ⩾20% excess cardiovascular disease at 60 to 82 years of age, relative to cohorts born without exposure to the influenza epidemic, either prenatally or postnatally (defined by the quarter of birth), in the 1982-1996 National Health Interview Surveys of the USA. Males showed stronger effects of influenza on increased later heart disease than females. Adult height at World War II enlistment was lower for the 1919 birth cohort than for those born in adjacent years, suggesting growth retardation. Calculations on the prevalence of maternal infections indicate that prenatal exposure to even uncomplicated maternal influenza may have lasting consequences later in life. These findings suggest novel roles for maternal infections in the fetal programming of cardiovascular risk factors that are independent of maternal malnutrition.

Birth Cohort and the Black-White Achievement Gap: The Roles of Access and Health Soon After Birth

One literature documents a significant, black-white gap in average test scores, while another finds a substantial narrowing of the gap during the 1980s, and stagnation in convergence after. We use two data sources – the Long Term Trends NAEP and AFQT scores for the universe of applicants to the U.S. military between 1976 and 1991 – to show: 1) the 1980s convergence is due to relative improvements across successive cohorts of blacks born between 1963 and the early 1970s and not a secular narrowing in the gap over time; and 2) the across-cohort gains were concentrated among blacks in the South. We then demonstrate that the timing and variation across states in the AFQT convergence closely tracks racial convergence in measures of health and hospital access in the years immediately following birth. We show that the AFQT convergence is highly correlated with post-neonatal mortality rates and not with neonatal mortality and low birth weight rates, and that this result cannot be explained by schooling desegregation and changes in family background. We conclude that investments in health through increased access at very early ages have large, long-term effects on achievement, and that the integration of hospitals during the 1960s affected the test performance of black teenagers in the 1980s.

Intergenerational Economic Mobility in the U.S., 1940 to 2000

We use two sample instrumental variables to estimate intergenerational economic mobility from 1940 to 2000. We find intergenerational mobility increased from 1940 to 1980 but declined sharply thereafter, a pattern similar to cross-sectional inequality trends. However, the returns to education account for only some of these patterns. The time- series may help to reconcile previous findings in the intergenerational mobility literature. Our estimates imply a somewhat different pattern for the intergenerational income correlation, a measure insensitive to changes in cross-sectional inequality that has implications for rank mobility. We find the post-1980 decline in intergenerational rank mobility marks a return to historical levels. Consequently, by 2000, the rate of intergenerational movement across the income distribution appears historically normal, but, as cross-sectional inequality has increased, earnings are regressing to the mean at a slower rate, causing economic differences between families to persist longer than earlier in the century.

A Nonparametric Analysis of Black-White Differences in Intergenerational Income Mobility in the United States

This paper concerns the problem of inferring the effects of covariates on intergenerational income mobility, i.e. on the relationship between the incomes of parents and future earnings of their children. We focus on two different measures of mobility - (i) traditional transition probability of movement across income quantiles over generations and (ii) a new direct measure of upward mobility, viz. the probability that an adult childs relative position exceeds that of the parents. We estimate the effect of possibly continuously distributed covariates from data using nonparametric regression and average derivatives and derive the distribution theory for these measures. The analytical novelty in the derivation is that the dependent variables involve nonsmooth functions of estimated components - marginal quantiles for transition probabilities and relative ranks for upward mobility - thus necessitating nontrivial modifications of standard nonparametric regression theory. We use these methods on US data from the National Longitudinal Survey of Youth to study black-white differences in intergenerational mobility, a topic which has received scant attention in the literature. We document that whites experience greater intergenerational mobility than blacks. Estimates of conditional mobility using nonparametric regression reveal that most of the interracial mobility gap can be accounted for by differences in cognitive skills during adolescence. The methods developed here have wider applicability to estimation of nonparametric regression and average derivatives where the dependent variable either involves a preliminary finite-dimensional estimate in a nonsmooth way or is a nonsmooth functional of ranks of one or more random variables.

The impact of Rosenwald Schools on Black achievement

The black-white gap in schooling among southern-born men narrowed sharply between the world wars. From 1914 to 1931, nearly 5,000 schools were constructed as part of the Rosenwald Rural Schools Initiative. Using census data and World War II records, we find that the Rosenwald program accounts for a sizable portion of the educational gains of rural southern blacks. We find significant effects on school attendance, literacy, years of schooling, cognitive test scores, and northern migration. The gains are highest in the most disadvantaged counties, suggesting that schooling treatments have the largest impact among those with limited access to education.

The Growing Importance of Family: Evidence from Brothers Earnings

We examine between-brother correlation of earnings, family income, and wages from two cohorts of the National Longitudinal Surveys. Young brothers who entered the labor market in the 1970s had lower correlations of economic outcomes than did those who entered in the 1980s and early 1990s. Neither the rising brother correlation in education nor the rising return to schooling accounts for much of the increase in the brother correlation in earnings. These results suggest that family and community influences other than years of education that are shared by brothers have become increasingly important in determining economic outcomes.

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.

The Mis-Measurement of Permanent Earnings: New evidence from Social Security Earnings Data

This study investigates the reliability of using short-term averages of earnings as a proxy for permanent earnings in empirical research. An earnings dynamics model is estimated on a large sample of men covering the period from 1983 to 1997 following the cohort-based methodology of Baker and Solon (1999). The analysis uses a unique dataset that matches men in the 1984, 1990 and 1996 Surveys of Income and Program Participation (SIPP) to the Social Security Administrations Summary Earnings Records (SER). The results confirm that using a short-term average of earnings can lead to spurious estimates of the effect of lifetime earnings on a particular outcome. In addition, the transitory variance appears to vary considerably over the lifecycle. The share of earnings variance due to transitory factors is higher among blacks and the persistence of transitory shocks appears to be greater for this group as well. Finally, the transitory variance appears to be a more important factor in explaining the overall earnings variance of college educated men than those without college.