This dissertation consists of three essays in health economics. The three chapters focus specifically on prescription drug use and treatment in various national and state settings and evaluate the impact of government policies and interventions on this sector of the health care market. The first two chapters focus on opioid prescribing in the United States. Prescription drug monitoring programs (PDMPs or PMPs)—online systems that health care providers and pharmacists can use to query patient prescription records—are one of the most widely-used state tools in regulating the prescribing and dispensing of opioids. However, the staggered adoption of PDMPs over time has created opportunities for patients to evade monitoring by going to a state that does not have a PDMP. Chapter 1 evaluates how spillovers attributable to policy non-coordination between neighboring states impact the effectiveness of PDMPs. I find that after prescribers gain access to PDMPs, opioid volume and prescription opioid deaths decrease in counties with a PDMP that are insulated from opportunities for evasion. I find a similar effect in counties with a PDMP that are exposed to evasion. This suggests that exposure to evasion through proximity to non-PDMP areas does not significantly attenuate the policy effect. I also find evidence that opioid volume and prescription opioid deaths decrease in counties without a PDMP that are exposed to spillovers from counties with the policy. Illicit opioid deaths are not affected in any counties with a PDMP but decrease in counties without a PDMP that are exposed to spillovers. I discuss the potential mechanisms through which spillovers may operate. Chapter 2, which is joint work with Adam Sacarny, David Powell, Ian Williamson, Weston Merrick, and Mireille Jacobson, evaluates how "nudge" interventions can impact the behavior of clinicians prescribing controlled substances. PMPs aim to reduce inappropriate opioid prescribing but may be underutilized by prescribers. We conduct a randomized clinical trial of 12,000 clinicians in Minnesota to test whether letters to providers can increase PMP use and decrease potentially dangerous opioid co-prescriptions. In this study, we focus on the co-prescribing of opioids and benzodiazepines and the co-prescribing of opioids and gabapentinoids. We find that letters that mention the state's new PMP use mandate increase PMP search rates and the share of clinicians with PMP accounts but have no significant effect on co-prescribing. Letters with only information about the risks of co-prescribing and a list of co-prescribed patients have no detected effect on primary outcomes of interest. We also explore the impact of the letters on additional search and prescribing outcomes. Our results highlight the potential for simple letter-based interventions to encourage engagement with PMPs and facilitate better-informed prescribing of opioids and other medications. Finally, Chapter 3 studies the prescription drug market in Japan, examining how changes in health care prices faced by patients can influence demand. I exploit a feature of the Japanese healthcare system, where an individual's coinsurance rate is determined primarily by their age, to evaluate the impact of a change in patient cost sharing on total prescription drug spending. I contribute to the existing literature by investigating heterogeneous effects by patient sex and drug therapeutic class (focusing on cardiovascular drugs, antibiotics, vitamins, antihistamines, and psychotropic drugs). I find that for the whole sample, price elasticity of spending for prescription drugs is comparable to previous estimates of price elasticity of spending for general medical services. I find no evidence of heterogeneous effects by sex over the whole sample of prescriptions, but I do find statistically significant differences between women and men within therapeutic drug classes. I also conduct exploratory analysis on the effect of changes in patient cost sharing on prescription drug volume. I estimate a price elasticity of demand for prescription drugs that is larger than previous estimates of demand elasticity for general medical services. I also find evidence that physicians do not respond on the intensive margin by prescribing more expensive medications. Although Japanese patients are more likely to be prescribed brand-name drugs, patients using generic medications may be more price sensitive to changes in patient cost sharing.

O objetivo do presente estudo foi verificar empiricamente as implicações da diversificação corporativa, através do efeito de coinsurance, nas finanças e no investimento corporativo através de dois canais específicos: o custo da dívida externa bancária das empresas e a probabilidade de ocorrência de covenants com restrições à investimento. Para alcançar esse objetivo, estimou-se dois modelos que controlam a endogeneidade da decisão de diversificar através da utilização de variáveis instrumentais. Não foi possível, através dos dados utilizados no estudo, evidenciar que a diversificação corporativa impacta o custo do financiamento externo bancário das empresas. O estudo encontrou evidências, ainda que fracas, de que a diversificação corporativa reduz a probabilidade de ocorrência de covenants com restrições a gastos em investimento nos contratos de financiamento bancário. / The purpose of this study is to empirically verify the implications of corporate diversification, through coinsurance effect, in corporate finance and investment through two specific channels: the cost of bank borrowing and the likelihood of covenants with investment restrictions. To achieve this goal, this study estimated two models that control the endogeneity of the diversification decision by using an instrumental variables approach. The results do not show evidences that corporate diversification affects the cost of bank borrowing. In addition, the analysis suggests that corporate diversification reduces the likelihood of covenants with investment restrictions in bank borrowing contracts. Although the evidence is weak, it brings a new insight into how corporate diversification affects corporate results.

O objetivo do presente estudo foi verificar empiricamente as implicações da diversificação corporativa, através do efeito de coinsurance, nas finanças e no investimento corporativo através de dois canais específicos: o custo da dívida externa bancária das empresas e a probabilidade de ocorrência de covenants com restrições à investimento. Para alcançar esse objetivo, estimou-se dois modelos que controlam a endogeneidade da decisão de diversificar através da utilização de variáveis instrumentais. Não foi possível, através dos dados utilizados no estudo, evidenciar que a diversificação corporativa impacta o custo do financiamento externo bancário das empresas. O estudo encontrou evidências, ainda que fracas, de que a diversificação corporativa reduz a probabilidade de ocorrência de covenants com restrições a gastos em investimento nos contratos de financiamento bancário. / The purpose of this study is to empirically verify the implications of corporate diversification, through coinsurance effect, in corporate finance and investment through two specific channels: the cost of bank borrowing and the likelihood of covenants with investment restrictions. To achieve this goal, this study estimated two models that control the endogeneity of the diversification decision by using an instrumental variables approach. The results do not show evidences that corporate diversification affects the cost of bank borrowing. In addition, the analysis suggests that corporate diversification reduces the likelihood of covenants with investment restrictions in bank borrowing contracts. Although the evidence is weak, it brings a new insight into how corporate diversification affects corporate results.

O objetivo do presente estudo foi verificar empiricamente as implicações da diversificação corporativa, através do efeito de coinsurance, nas finanças e no investimento corporativo através de dois canais específicos: o custo da dívida externa bancária das empresas e a probabilidade de ocorrência de covenants com restrições à investimento. Para alcançar esse objetivo, estimou-se dois modelos que controlam a endogeneidade da decisão de diversificar através da utilização de variáveis instrumentais. Não foi possível, através dos dados utilizados no estudo, evidenciar que a diversificação corporativa impacta o custo do financiamento externo bancário das empresas. O estudo encontrou evidências, ainda que fracas, de que a diversificação corporativa reduz a probabilidade de ocorrência de covenants com restrições a gastos em investimento nos contratos de financiamento bancário. / The purpose of this study is to empirically verify the implications of corporate diversification, through coinsurance effect, in corporate finance and investment through two specific channels: the cost of bank borrowing and the likelihood of covenants with investment restrictions. To achieve this goal, this study estimated two models that control the endogeneity of the diversification decision by using an instrumental variables approach. The results do not show evidences that corporate diversification affects the cost of bank borrowing. In addition, the analysis suggests that corporate diversification reduces the likelihood of covenants with investment restrictions in bank borrowing contracts. Although the evidence is weak, it brings a new insight into how corporate diversification affects corporate results.

保險業承擔社會大眾轉嫁之風險，其自身亦需要透過風險之分散，以避免危險過度集中，而危及永續經營之能力。而保險市場之專業保險人間，常透過彼此技術之結合運用，達風險分散之目的。其中保險聯營，即為典型聯合數保險人之能量，合力承受特殊危險，協助個別保險人分散風險之方式，亦是目前各國或特定區域之保險業所偏好使用之制度之一。 保險聯營於我國已行之多年，保險業多利用其消納分散巨災或高度風險，抑或配合政府保險政策設立組織，對於我國保險市場而言，具有不可或缺之重要性。然而，保險聯營制度因為譯名與共同保險類似，導致實務對於此兩種同為保險人風險分散之制度產生觀念性之混淆，因無法確切了解其區別，所以產生立法上之錯誤及運作上之爭議。 本文以「保險聯營制度之研究-兼論保險業之風險分散方式」為題，試圖透過深入探討保險聯營制度，並比較其他類似方式，包括共同保險、再保險及交換業務等，以釐清各制度之差異，了解其功能、運作及契約當事人之法律關係；其次則介紹國內風險分散機制，以分析其本質，並就我國保險聯營實務問題為探究與建議。 本文研究結果發現，共同保險、再保險、交換業務及保險聯營制度，即便外觀及功能上多有重疊，但實際上係屬不同之機制。而國內風險分散機制，多數依其運作方式雖得歸類於保險聯營組織，惟究其與會員間之約定，得發現其混合其他風險分散機制之性質，因此不能單純以單一制度視之。關於保險聯營制度之實務問題探討，我國實務因對於「共保」兩字概念涵括範圍定義不一，造成保險法第一百四十四條之一之立法用字有所爭議，本文以為立法條文應儘量以明確用字，降低法律適用模糊的可能性；而聯營組織之型態，應以其功能性區別之，即組織本身若直接承接危險者或有其他對外代表性者，則應成立法人組織，使其享有法人權利，並履行法人義務；最後於公平法限制競爭之探討上，考量到保險聯營設立之特殊性，公平會之審查權限應受限縮，倘聯營組織之設立具備合理性及必要性，且其成效對於社會有顯著正面價值，應可排除公平法之適用。

在社會與商業性健保之醫療保障不足的情形下，重大傷病的龐大醫療費用 與醫療費用的上漲仍可能致使社會大眾對於醫療費用有沉重的負擔，故本 文將藉由美國近年來快速成長的高額醫療費用保險以作為我國發展高額醫 療保障保險的參考；本文並將保險人為避免道德危險與控制醫療資源的浪 費的措施作一探討。本文共分為五個章節，第一章旨在說明本文之研究動 機、目的、方法、範圍與限制。第二章在說明美國高額醫療費用保險之起 源、意義、內容與其要點。第三章旨在說明影響高額醫療費用保險費計算 之因素，及其純保費、毛保費與準備金之計算公式。第四章旨在探討現今 我國社會保險與商業健康保險之給付內容，並就現有高額醫療費用保險保 單進行深入的瞭解；此外，並針對未來我國高額醫療費用保險之發展及限 制亦提供論述。第五章旨在就本文各章節研究之心得，作一總結；並對國 內的情況提出建議。