Thesis advisor: Andrew Beauchamp / Thesis advisor: Mathis Wagner / This dissertation considers changes of health insurance system of United States that affect health outcomes and labor market outcomes of population. The first chapter examines how Medicaid policy aimed to improve health status of low-income parents affects the health outcomes of young children. Estimates from variations in Medicaid rules across states and over time, show that there exist positive spillover effects on children from Medicaid expansions targeting parents. The child mortality declines more in states with higher level of generosity in Medicaid policy and the effect is larger among black children. Simulations indicate that recent Medicaid expansion under Affordable Care Act Reform can deepen the existing child mortality disparity across states due to different adoption of Medicaid expansion for low income adult population. The second chapter examines Massachusetts health care reform and its impact on labor market outcomes of older males approaching retirement. I find that older males are more likely to remain in full-time employed status rather to choose early retirement, and part-time employment increased only among low-income population who are eligible for subsidized health insurance. The results suggests that there exists employment-lock effect from increase of employers providing employersponsored health insurances following the reform. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.