Owen Thompson

Genetic mechanisms in the intergenerational transmission of health

This paper uses a sample of adoptees to study the genetic mechanisms underlying intergenerational associations in chronic health conditions. I begin by estimating baseline intergenerational models with a sample of approximately 125,000 parent-child pairs, and find that children with a parent who has a specific chronic health condition are at least 100% more likely to have the same condition themselves. To assess the role of genetic mechanisms in generating these strong correlations, I estimate models using a sample of approximately 2400 adoptees, and find that genetic transmission accounts for only 20-30% of the baseline associations. As falsification tests, I repeat this exercise using health measures with externally established levels of genetic determination (height and chicken pox), and the results suggest that comparisons of biological and adopted children are a valid method of isolating genetic effects in this sample. Finally, to corroborate these adoptee-based estimates, I examine health correlations among monozygotic twins, which provide an upper bound estimate of genetic influences, and find a similarly modest role for genetic transmission. I conclude that intergenerational health transmission is an important hindrance to overall socioeconomic mobility, but that the majority of transmission occurs through environmental factors or gene-environment interactions, leaving scope for interventions to effectively mitigate health persistence.

Economic Background and Educational Attainment: The Role of Gene- Environment Interactions

On average, children from less economically privileged households have lower levels of educational attainment than their higher-income peers, and this association has important implications for intergenerational mobility and equality of opportunity. This paper shows that the income-education association varies greatly across groups of children with different versions of a specific gene, monoamine-oxidase A (MAOA), which impacts neurotransmitter activity. For children with one MAOA variant, increases in household income have the expected positive association with education. For children with another variant, who comprise over half of the population, this relationship is much weaker. These results hold when the interactive effects are identified using genetic variation between full biological siblings, which genetic principles assert is as good as randomly assigned.

Educational mobility across three generations of American women

We analyze the intergenerational transmission of education in a three-generation sample of women from the 20th century US. We find strong three-generation educational persistence, with the association between the education of grandmothers and their granddaughters approximately two times stronger than would be expected under the type of first-order autoregressive transmission structure that has been assumed in much of the existing two-generation mobility literature. These findings are robust to using alternative empirical specifications and sample constructions, and are successfully replicated in a second independently drawn data set. Analyses that include males in the youngest and oldest generations produce very similar estimates. A variety of potential mechanisms linking the educational outcomes of grandparents and grandchildren are discussed and where possible tested empirically.

Genes and the intergenerational transmission of BMI and obesity

This paper compares the strength of intergenerational transmission of body mass index (BMI) and obesity in a sample of adoptees relative to a matched sample of biological children with similar observable characteristics. We find that BMI and obesity are strongly correlated among biological parent-child pairs, but there are no significant intergenerational associations in these health traits among adoptive parent-child pairs. The intergenerational elasticity of BMI for children to their parents is 0.2 in the matched biological sample, but indistinguishable from zero for adopted children with a standard error more than three times as large as the coefficient. Under reasonable assumptions, these findings indicate that the intergenerational transmission of BMI and obesity occurs primarily through genetic mechanisms. Additional analyses of transmission rates by parental gender and among step-parents and step-children support this conclusion. The role of determinants of BMI and obesity in the household environment in relation to our findings is discussed. Given the negative consequences of obesity on earnings and other economic measures, our results suggest that the genetic transmission of weight problems contributes substantially to intergenerational persistence in economic outcomes.

The long-term health impacts of Medicaid and CHIP

This paper estimates the effect of US public health insurance programs for children on health. Previous work in this area has typically focused on the relationship between current program eligibility and current health. But because health is a stock variable which reflects the cumulative influence of health inputs, it would be preferable to estimate the impact of total program eligibility during childhood on longer-term health outcomes. I provide such estimates by using longitudinal data to construct Medicaid and CHIP eligibility measures that are observed from birth through age 18 and estimating the effect of cumulative program exposure on a variety of health outcomes observed in early adulthood. To account for the endogeneity of program eligibility, I exploit variation in Medicaid and CHIP generosity across states and over time for children of different ages. I find that an additional year of public health insurance eligibility during childhood improves a summary index of adult health by.079 standard deviations, and substantially reduces health limitations, chronic conditions and asthma prevalence while improving self-rated health.

Head Start’s Long-Run Impact Evidence from the Program’s Introduction

This paper estimates the effect of Head Start on health, education, and labor market outcomes observed through age 48. I combine outcome data from the NLSY79 with archival records on early Head Start funding levels and for identification exploit differences across counties in the introduction timing and size of local Head Start programs. This allows me to compare the long-term outcomes of children who were too old for Head Start when the program was introduced in their county with the outcomes of children who were sufficiently young to be eligible. I find that individuals from counties that had an average-sized program when they were in Head Start’s target age range experienced a

School Desegregation and Black Teacher Employment

2,199 increase in annual adult earnings, completed 0.125 additional years of education, were 4.6 percentage points less likely to have a health limitation at age 40, and overall experienced a 0.081 standard deviation improvement in a summary index of these and other outcome measures. Funding levels at ages outside of Head Start’s target range are not significantly correlated with long-term outcomes. Estimated treatment effects are largest among blacks, the children of lower-education parents, and children exposed to better funded Head Start programs—heterogeneity that is consistent with a causal program impact.

Fertility Decline in the Civil Rights Era

Prior to the racial integration of schools in the southern United States, predominantly African American schools were staffed almost exclusively by African American teachers as well, and teaching constituted an extraordinarily large share of professional employment among southern blacks. The large-scale desegregation of southern schools occurring after passage of the 1964 Civil Rights Act represented a potential threat to this employment base, and this paper estimates how student integration affected black teacher employment. Using newly assembled archival data from 781 southern school districts observed between 1964 and 1972, I estimate that a school district transitioning from fully segregated to fully integrated education, which approximates the experience of the modal southern district in this period, led to a 25% reduction in black teacher employment. A series of tests indicate that these employment reductions were not due to school district self-selection into desegregation or unobserved district characteristics associated with desegregation. Additional estimates using synthetic cohorts from the Decennial Censuses indicate that displaced southern black teachers either entered lower skill occupations within the South or migrated out of the region to continue teaching, and that southern school districts compensated for reduced black teacher employment by employing fewer total teachers and by increasing their recruitment of white teachers, especially less experienced white teachers and white male teachers.

Gene-Environment Interaction in the Intergenerational Transmission of Asthma: HEALTH TRANSMISSION

Large black-white fertility differences are a key feature of US demography, and are closely related to the broader dynamics of US racial inequality. To better understand the origins and determinants of racial fertility differentials, this paper examines fertility patterns in the period surrounding passage and implementation of the 1964 Civil Rights Act, which precipitated a period of rapid socioeconomic and political progress among African Americans, with these gains strongly concentrated in the South. I first show that the relative fertility of southern black women precipitously declined immediately after 1964. Specifically, as of 1964 the general fertility rate of southern black women was 53 births greater than the general fertility rate of southern white women, but by 1969 this gap had fallen to 33 births, a decline of approximately 40% in five years. The black-white fertility gap outside of the South was unchanged over this period. Measures of completed childbearing similarly show rapid black-white fertility convergence in the South but not in the North. An analysis of potential mechanisms finds that a substantial share of the observed fertility convergence can be explained by relative improvements in the earnings of southern blacks, and that the historical intensity of slavery and lynching activity are the strongest spacial correlates of fertility convergence Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Gene-Environment Interaction in the Intergenerational Transmission of Health

Researchers have found strong linkages between parent and child health, but the mechanisms underlying intergenerational health transmission are not well understood. This paper investigates how the importance of genetic health transmission mechanisms varies by environmental conditions in the case of pediatric asthma, the single most common chronic health condition among American children. Using a sample that includes approximately 2000 adoptees and a large number of similar biological families, I find that the relative importance of genetic transmission differs strongly by socioeconomic status (SES). In high SES families, parent-child asthma associations are approximately 75% weaker among adoptees than biological children, suggesting a dominant role for genetic transmission. In lower SES families, parent-child asthma associations are virtually identical across biological and adoptive children, suggesting a negligible role for genetic transmission. A potential interpretation of this difference is that as environmental conditions affecting asthma improve among higher SES children, an increasingly large share of asthma variation is due to genetics. Copyright