Research

Abstract. The National Association for Stock Car Auto Racing (NASCAR) and Automobile Racing Club of America (ARCA) races continued to use leaded gasoline until 2007, despite the removal of leaded gasoline from on-road vehicles long ago. Exploiting this novel quasi experiment, I study how airborne lead exposure affected birth outcomes using administrative birth records linked to race events at Texas Motor Speedway (TMS) in Fort Worth, Texas. Mothers living within 25 km of TMS see a reduction in infant birthweight, shortened gestation length, and an increased probability of low birthweight before the ban of lead from NASCAR and ARCA races, while a post-ban placebo yields coefficients near zero. To translate race-day exposures into blood lead burdens, I developed a pregnancy-specific physiologically based pharmacokinetic (PBPK) model that simulates maternal and fetal daily blood lead trajectories. I find that a one-standard-deviation increase in second-trimester PBPK blood lead reduces birthweight by approximately 63 grams. A potential mechanism suggests that lead increases gestational hypertension and shortens gestation, and these effects disappear after the transition to unleaded fuel. These findings suggest that even a relatively low level of lead can have a meaningful effect on maternal and infant health.

Abstract. We estimate well-being among older rural Americans with an expected utility framework and simulations using longitudinal data spanning nearly 30 years from the Health and Retirement Study. At age sixty, we find mean rural consumption expenditures of $24,105, a retirement probability of 53%, and a remaining life expectancy of 20.3 years for the cohort born 1931–36. When adjusting life expectancy for living in poor health, we obtain an age sixty quality adjusted life expectancy (QALE) of only 15.4 years. Our welfare metric suggests well-being among rural residents who report loneliness is only about half that of the non-lonely rural residents—largely driven by substantial consumption and QALE gaps. We also document substantial regional variation in rural well-being. Moreover, we find that older rural Americans are generally falling further behind older urban Americans across birth cohorts. Most of this widening gap is driven by declining relative consumption and wealth as opposed to health.

Abstract. This paper examines how the economic effects of population aging vary across space. Using U.S. county data from 2000 to 2020, we estimate the impact of changes in the share of adults aged 60 and older on GDP per capita growth. We instrument for aging using lagged age structure from historic censuses to address endogeneity. We find that a 10 percent increase in the 60+ population share reduces GDP per capita by roughly 4-5 percent, but this average masks substantial spatial heterogeneity. Aging has little measurable effect in large, economically integrated labor markets, while generating sizable growth declines in smaller and more isolated regions. Sectoral analysis reveals contractions in agriculture, construction, and manufacturing alongside expansions in health care and professional services; however, only economically integrated counties appear able to offset sectoral contraction and avoid aggregate losses. These results suggest that the local consequences of demographic aging depend not only on industrial structure but also on regional integration and labor market connectivity.

Abstract. Exploiting natural experiments in maternal exposure to tetraethyl-lead arising from the differential phase-out of leaded gasoline across the United States, and from the exogenous migration behavior of mothers during pregnancy, we find consistent evidence that fetal exposure to lead through the maternal blood lead pathway significantly affects infant health. Across an ensemble of tests, we find that an increase in maternal blood lead: 1) decreases infant birthweight; 2) increases the risk of low birthweight; 3) shortens gestation length; and 4) increases the risk of prematurity. These results are robust to various measurement operations of our treatment variable, the relaxation of case inclusion criteria, and the substitution of our blood lead treatment variable for proxy measures of lead exposure. Moreover, we satisfy a divergent validity test by falsifying our causal channel of maternal blood lead with analyses of the lead-independent outcome of infant sex. While the flow of lead into the lived environment has decreased substantially since of the phase-out of leaded gasoline, exposure to legacy lead sources remains a public health problem with measurable economic costs.

Abstract. This paper studies whether emotionally salient events affect physician decision-making and maternal health during childbirth using evidence from NCAA football games. We document three main findings. First, the probability of a non-cesarean, non-induced birth occurring around NCAA game days increases, consistent with deliveries being shifted around games. Second, the probability of maternal complications increases by 0.23 percentage points on game weekends, which is a 19 percent increase relative to the baseline rate. Third, these effects are concentrated among low-SES, uninsured, and WIC mothers, while we find little evidence of differences by race. The results suggest that salient events such as NCAA football games, particularly those played on weekends when staffing is typically low, can influence physician behavior and worsen maternal outcomes.

Abstract. This paper examines whether in-utero exposure to extreme heat worsens birth outcomes in Texas, and whether urban heat islands (UHIs) amplify such effects. Using 2.5 million Texas birth records (2003--2010) linked to tract-level daily temperature and NLCD impervious surface coverage, the preliminary findings suggest that heat has no significant effect on fetal growth (birth weight or low birth weight) conditional on gestational age, which may reflect selection via early fetal loss, behavioral adaptation, or other channels. Results are provisional.