Anderson Ospino - Research

Job Market Paper: Does free health care mitigate the effect of prenatal air pollution on birth outcomes?

Environmental and epidemiological research has linked prenatal air pollution exposure to the incidence of fetal and infant death, adverse birth outcomes, and worse outcomes in adulthood and across generations. Moreover, the effects of ambient air pollution depend on social and economic factors. This paper tests whether access to free prenatal health care mitigates the adverse health effects of exposure to air pollution in-utero. I study how the expansion of Medicaid (publicly-provided health insurance for low-income households) changed the effect of prenatal exposure to sulfur dioxide (SO2) on fetal death and birth outcomes. Theoretically, the effect is ambiguous: Even if health care mitigates the biological impact of air pollution, there could be a substitution between access to health care and pollution avoidance. High SO2 concentrations increased fetal deaths, and Medicaid’s expansion attenuated this effect. Estimating the impact of Medicaid on the SO2-birth outcome relationship is empirically challenging because the infants marginally saved by Medicaid could be positively or negatively selected. The analysis of traditional outcome variables (e.g., birthweight, low birthweight rate) suggests that Medicaid had no impact or even intensified the damage of SO2 on health at birth. To account for the possibility of sample selection, I instead analyzed the number of non-low birth weight (i.e., healthy) infants per woman of reproductive age (nlbw/w). Using this dependent variable, I find that Medicaid mitigated the effect of SO2 on (nlbw/w) in low-pollution areas and at the national level. Furthermore, the reduction was larger for blacks than whites; thus, Medicaid improved environmental justice in the US by shrinking the gap in the health effects of in-utero air pollution between races.

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Revising the Effects of Sulfur Dioxide on Birth Outcomes

Estimating the effects of air pollution is a critical input for the design of environmental regulation. This paper shows that the estimates of sulfur dioxide (SO2) effects on birth outcomes are highly sensitive to the window used to measure exposure during the prenatal period. Measuring exposure from conception to birth, I find a negative impact of SO2 on birthweight. In contrast, the estimate is positive when exposure is measured from conception to 39 weeks. Using each county’s 52-week lagged SO2 concentrations as a placebo, I find that using a fixed 39-week window from the date of conception is the most robust methodology. However, this methodology's estimates indicate higher SO2 concentrations increase birth weight. I present evidence suggesting that this counterintuitive result is caused by livebirth bias (i.e., the infants that survive pollution shocks are positively selected). I overcome this problem by using the number of infants born with non-adverse outcomes per woman of reproductive age as the dependent instead of traditional outcomes (e.g., birthweight, low birthweight, or preterm rate). Using these variables, I find that SO2 worsens health at birth, and its effects are marginally increasing (i.e., the SO2-Birth outcome damage function is convex). Furthermore, the effect is larger for blacks than whites.

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Pre-Doctoral Research

Financial Globalization and Market Volatility: An empirical Appraisal (With Tito Cordella, John Hopkins-SAIS)-

World Bank Policy Research Working Paper 8091 (2017)

Work in Progress

Does free health care mitigates the impact of extreme temperatures on birth outcomes?
Does food stamps mitigate the impacts of air pollution on infants' health?
Disentangling the interaction term of two continuous variables in a Two-way fixed effects panel data model