My dissertation, consisting of three chapters, considers the role of the childhood circumstances on adulthood measures of economic wellbeing. The first two chapters analyze a large expansion of public health insurance to children from low-income families in the United States. The third and final chapter analyzes the impact of childhood exposure to lead (Pb) in India. In Chapter 1, I examine one of the largest ever expansions of Medicaid, health insurance provided by the state at very low-cost to low-income Americans. In 1990, Congress passed a bill that extended Medicaid eligibility for children living below the poverty line from age 6 to age 18. This expansion, however, applied only to individuals born on or after October 1, 1983. Using a research design that exploits this sudden change in eligibility with respect to date of birth (a regression discontinuity design), I estimate the impact that the policy had on Medicaid enrollment rates. I find that enrollment rose specifically among Black children, and I offer potential explanations for why children of other races do not enroll despite becoming eligible. This finding contributes to a large literature on the puzzlingly low usage of social programs. In Chapter 2, I continue investigating this large expansion of youth Medicaid, but I shift focus to adulthood outcomes for individuals born around the October 1, 1983 cutoff. Namely, I study incarceration. I show that Black children born just after the cutoff are 5 percent less likely to be incarcerated by age 28, driven primarily by a decrease in incarcerations connected to financially motivated offenses. Children of other races, who (as discussed in Chapter 2) experienced almost no gain in Medicaid coverage as a result of the policy, demonstrate no such decline. I find that reduced incarceration in adulthood substantially offsets the initial costs of expanding eligibility. This result provides a clear demonstration for a commonly held view that investments in children and in public health systems can produce substantial social benefits, in addition to private ones. In Chapter 3, I turn attention to a developing-country context, specifically India, where environmental factors play an outsized role in child development. I study a large reduction in ambient exposure to lead, a neurotoxic substance that is particularly harmful to infants and children. Specifically, I analyze the impact that the phase-out of leaded gasoline had on the educational trajectories of children in India. I estimate this effect by leveraging the city-by-city implementation of the phase-out in the late 1990s and early 2000s. I find that lead exposure had significantly suppressed educational attainment in India. This finding adds to the evidence that environmental factors in early life can strongly affect markers wellbeing in later life