This thesis consists of three chapters on various health economics topics. The first chapter investigates how physicians respond to Medicare reimbursement rate changes. The Affordable Care Act increased reimbursements in four states differentially across physicians. I run a difference in difference (DID) comparing physicians with higher reimbursement increases to those with lower increases. I focus on office-based physicians and find that physicians with higher reimbursement increases were more likely to continue providing office-based care, while physicians with relatively lower increases were more likely to move all their provision to non-office facilities (e.g., hospitals), which suggests vertical integration. I also find that physi...