This thesis focuses on infant and maternal health through the examination of different government regulated policy interventions. Specifically, this thesis comprises of three essays. First, I examine the effect of a reduction in coal-fired power plant emissions on infant health outcomes of downwind counties. Second, I analyze how limiting lawyers’ contingency fees affects physicians’ decision to perform C-sections on women and, ultimately, its effect on infant mortality. The third, and final, paper investigates whether or not medical malpractice tort reforms have altered physicians’ decision to take part in defensive medicine. Chapter 1 examines the Clean Air Interstate Rule (CAIR) which mandated the reduction of power plant emissions in the eastern United States. This policy improved air quality in neighbouring downwind counties, greatly reducing exposure to a specific form of pollution—fine particulate matter. I investigate the impact of this reduction exposure on birth outcomes using data from the U.S. Natality Detail Files. I find that female babies experience improvements in premature birth and low/very low birth weight status which are driven by the reduction in prematurity. I also focus on full-term babies to better isolate the impact of prematurity from fetal growth on birth weight. Consistent with recent work, I find that full-term male babies experience an increase in birth weight, demonstrating an improvement in intrauterine growth due to lower exposure to fine particulates. Finally, I find a reduction in infant mortality for babies whose mothers were categorized as “high-risk” pregnancies, suggesting that reduced exposure may lead to improved birth outcomes among those most at risk. Chapter 2 analyzes a limit on contingency fees for lawyers in medical malpractice cases enacted in Nevada. Generally, such limits are thought to change the composition of liability cases as they induce lawyers to drop more frivolous cases in favour of ones involving death and serious injury. Inadvertently, obstetricians faced a greater fear of litigation. Applying synthetic control methods, I find a 2.8 percentage point increase in the C-section rates of high school dropout patients, translating to a ten percent increase after the reform. There is no statistically significant difference in C-section rates after the enactment of the reform on patients with at least a college degree, and further, no statistically significant effect on infant mortality. Limiting contingency fees in medical malpractice cases induces obstetricians to engage in defensive medicine by performing more C-sections on low income patients, illustrating that tort reform can alter physician procedural patterns, albeit in heterogeneous ways. Chapter 3 continues with the theme of government regulated policy intervention by examining the effects of medical malpractice tort reform on maternal and infant health. Numerous papers examined the effects of tort reforms on physician behaviour using data from the 1990s. However, a medical malpractice “crisis” in the early 21st century saw many US states adopt tort reforms to alleviate this issue. Using data from 1995 to 2012 I observe that tort reforms are not as effective as they once were. However, I find evidence that physicians’ procedural choices are affected by tort reforms. Not only are C-section rates and “preventable” complications affected by tort reforms, but I also observe that tort reforms influence physicians’ decisions with non-risky patients. Thesis Doctor of Philosophy (PhD)