During the past few decades, the United States health care market has experienced dramatic changes. One feature of the health care market that has stayed constant is the persistently large number of Americans who lack health insurance coverage. To date, research has primarily focused on how lack of insurance affects an individual's own health outcomes, health care utilization and economic well-being. Little is known about how the uninsured affect the provision of care to insured patients. In this dissertation, I aim to increase our understanding of the community effects of uninsurance in two distinct but closely related areas: patient health outcomes and hospital treatment patterns.

In the first essay, I examine the impact of uninsured patients on the health of the insured, focusing on one health outcome — the in-hospital mortality rate of insured heart attack patients. Overall, my results indicate that uninsured patients have an economically significant effect that increases the mortality rate of insured heart attack patients. I show that these results are not driven by unobserved characteristics of insured heart attack patients or hospitals and that they are robust to a host of specification checks.

In the second essay, I examine the impact of the uninsurance rate in the health care market of a hospital on its uncompensated care burden and on the provision of care to heart attack patients. My analysis suggests that the defaulted payments by uninsured patients impose a large fiscal burden on hospitals. I also find that hospitals make changes to their provision of care to heart attack patients when faced with higher uninsurance rates. In particular, my results suggest that hospitals are more likely to use intensive procedures and less likely to conduct these procedures in an inpatient setting when market uninsurance rates increase.