This dissertation consists of two essays that explain health outcomes and medical care in the United States. Health care has been a major concern of economists and policy makers. Policy intervention is one of the key factors that affect health outcomes, especially among low-income families. Welfare programs such as Medicaid and cash assistance are conventionally implemented to assist low-income families. The effectiveness of these efforts to improve health outcomes and medical utilization among low-income families is not entirely clear. As to the supply side of health care, the results of previous studies on how hospitals provide the services are mixed. Additionally, hospitals may compete to attract patients and generate spillover effects. ...