This dissertation thesis address how aggregate shocks affect insurance firms' risk management and asset investment decisions as well as the impact of these decisions on insurance prices and regulation. The first chapter develops a signaling model to examine how insurance firms choose among retention, reinsurance and securitization especially for catastrophe risks. The second chapter examines the determination of insurance prices in an integrated equilibrium framework where insurers' assets may be subject to both idiosyncratic and aggregate shocks. The third chapter presents an empirical analysis of the hypothesized impacts of internal capital and asset risk on insurance prices as predicted by the results of the second chapter. The last chapter investigates the optimal design of insurance regulation to achieve the Pareto optimal asset and liquidity management by insurers as well as risk sharing between insurers and insurees. Chapter 1 provides a novel explanation for the predominance of retention and reinsurance relative to securitization in catastrophe risk transfer using a signaling model. An insurer's risk transfer choice trades off the lower signaling costs of reinsurance against the additional costs of reinsurance stemming from sources such as their market power, higher cost of capital relative to capital markets, and compensation for their monitoring costs. In equilibrium, the lowest risk insurers choose reinsurance, while intermediate and high risk insurance choose partial and full securitization, respectively. An increase in the loss size increases the average risk of insurers who choose securitization. Consequently, catastrophe risks, which are characterized by low frequency-high severity losses, are only securitized by very high risk insurers. Chapter 2 develops a unified equilibrium model of competitive insurance markets where insurers' assets may be exposed to idiosyncratic and aggregate shocks. We endogenize the relationship between insurance prices and insurers internal capital that potentially reconcile the conflicting predictions of previous theories that investigate the relation using partial equilibrium frameworks. Equilibrium effects lead to a non-monotonic U-shaped relation between insurance price and internal capital. Specifically, the equilibrium insurance price first decreases with a positive shock to the internal capital when it is below certain threshold level, and then increases with a positive shock the internal capital when it is above the threshold level. Further, we also derive another testable implication that an increase in the asset default risk increases the insurance price and decrease the insurance coverage. Chapter 3 studies the property and casualty insurance industry in periods from 1992 to 2012 based on the aggregate level of NAIC data. We show that the insurance price decreases with an increase in the surplus of insurance firms at the end of the previous year when the surplus is lower than 8.5 billion, and then increase when the surplus is higher than 8.5 billion. Our results provide support for the hypothesis of a U-shaped relationship between internal capital and insurance price. Our results also provide evidence for the positive relationship between asset portfolio risk and insurance price. Chapter 4 studies the effects of aggregate risk on the Pareto optimal asset and liquidity management by insurers as well as risk-sharing between insurers and insurers. When aggregate risk is low, both insurers and insurers hold no liquidity reserves, insurees are fully insured, and insurers bear all aggregate risk. When aggregate risk takes intermediate values, both insurees and insurers still hold no liquidity reserves, but insurers partially share aggregate risk with insurers. When aggregate risk is high, however, it is optimal to hold nonzero liquidity reserves, and insurees partially share aggregate risk with insurers. The efficient asset and liquidity management policies as well as the aggregate risk allocation can be implemented through a regulatory intervention policy that combines a minimum liquidity requirement when aggregate risk is high, "ex post" contingent on the aggregate state, comprehensive insurance policies, and reinsurance.

In many regions of the world, the solvency regulation of insurers is becoming more principle-based and market oriented. However, the exact forms of the solvency standards that are emerging in individual jurisdictions are not entirely consistent. A common risk and capital framework can level the global playing field and possibly reduce the cost of capital for insurers. In the thesis, a conceptual framework for measuring the insolvency risk of life insurance companies will be proposed. The two main advantages of the proposed solvency framework are that it addresses the issue of incentives in the calibration of the capital requirements and it also provides an associated decomposition of the insurer's insolvency risk by term. The proposed term structure of insolvency risk is an efficient risk summary that should be readily accessible to both regulators and policyholders. Given the inherent complexity of the long-term guarantees and options of typical life insurance policies, the term structure of insolvency risk is able to provide stakeholders with more complete information than that provided by a single number that relates to a specific period. The capital standards for life insurers that are currently existing or have been proposed in Canada, U.S., and in the EU are then reviewed within the risk and capital measurement framework of the proposed standard to identify potential shortcomings.

In many regions of the world, the solvency regulation of insurers is becoming more principle-based and market oriented. However, the exact forms of the solvency standards that are emerging in individual jurisdictions are not entirely consistent. A common risk and capital framework can level the global playing field and possibly reduce the cost of capital for insurers. In the thesis, a conceptual framework for measuring the insolvency risk of life insurance companies will be proposed. The two main advantages of the proposed solvency framework are that it addresses the issue of incentives in the calibration of the capital requirements and it also provides an associated decomposition of the insurer's insolvency risk by term. The proposed term structure of insolvency risk is an efficient risk summary that should be readily accessible to both regulators and policyholders. Given the inherent complexity of the long-term guarantees and options of typical life insurance policies, the term structure of insolvency risk is able to provide stakeholders with more complete information than that provided by a single number that relates to a specific period. The capital standards for life insurers that are currently existing or have been proposed in Canada, U.S., and in the EU are then reviewed within the risk and capital measurement framework of the proposed standard to identify potential shortcomings.

確保保險公司的清償能力一直是保險監理的重心。在所有施行的保險清償監理工具中，風險基礎資本（Risk-Based Capital, RBC）是目前為止最先進的代表。然銀行監理機關已經推薦涉險值（Value at Risk, VaR）系統為資本適足要求的工具，因此涉險值有很大的潛力成為下一代的保險資本適足要求工具，雖然尚未施行。由於保險監理的重要性以及RBC和VaR在其中扮演重要的角色，兩者相對上的精確性是我們所感興趣的。 本篇論文的目的是實際去比較RBC及VaR在破產預測上的相對精確性。我們以美國1995到1998年產險公司的實際清償記錄，用型1及型2錯誤檢視RBC及VaR的破產預測能力。RBC的數據直接從產險公司報給NAIC的年報上就可取得，而VaR的數據來自於我們所建立的現金流量模擬模型。既然RBC的數據是實際的數據，而VaR的估計值也是基於公司實際的財務數據而來，我們能以實例展現VaR相較於RBC的財務預警能力。 我們的結果顯示RBC沒有任何財務預警能力，換句話說，沒有一個破產公司的RBC值小於0.7（監理機關可以根據這個值關掉公司）。另一方面，VaR有較好的財務預警能力，但是它同時也會使許多財務健全的公司必須接受許多沒有必要的檢查。我們VaR模型的整體正確分類能力只比隨意分類稍微好一些。 雖然結果並不如原先預期的好，我們仍然對VaR成為保險監理工具抱持樂觀的態度，因為它是目前為止最嚴密也最先進的風險管理工具。我們認為這些結果可以藉由修正不適當的假設後獲得改善，未來研究可以先朝這個方向努力。 / Assuring insurance company solvency has always been the focal point of insurance regulation. Among the employed solvency regulation methods, RBC represents the currently state-of-the-art capital adequacy requirement. Bank regulators already advocated the use of VaR systems in capital adequacy requirements. Value at risk thus has great potential to be the next-generation capital adequacy regulation, although not implemented yet. Because of the importance of solvency regulation as well as the key role played in that regulation by RBC and VaR, the relative accuracy of RBC and VaR is of great interest. The purpose of this research is to empirically compare the relative effectiveness of RBC and VaR in predicting insolvency. Through the solvency record of property-casualty insurers in the United States from 1995 to 1998, we examine the Type I and Type II error of VaR and RBC in predicting insolvency. The RBC figures are readily available from the annual statement since 1994 and the VaR values come from a simulation model that we build up. Since the RBC figures are the “real” numbers and the VaR estimates also base on the companies’ real financial positions, our research will demonstrate how VaR is compared to RBC in early warning for real cases. Our result shows that RBC doesn’t have any prediction power. In other words, none of the bankrupt insurers has a RBC ratio lesser than 0.7, the threshold according to which the regulator can seize the company. On the other hand, VaR has good early warning ability, but also leads the regulator to take too much unnecessary actions on solvent companies. The overall ability of correct classification of our model is just a little stronger than arbitrary classification. Although our results are not as good as we expect, we are still optimistic about the use of VaR, the currently most comprehensive and advanced approach of risk management, as an insurance solvency regulation tool. We attribute the unsatisfactory outcome to some assumptions that may be inappropriate. Further researches can move toward this aspect.

保險公司清償能力一直是保險監理的重心，在所有現行的制度中風險基礎資本是最重要的，但此項制度仍有其缺點，因此其他動態分析模型被許多學者所提出，如涉險值及情境分析。雖然這些動態分析模型被學者所偏好，但監理機關仍須對這些模型的精確程度加以了解，這也是本篇論文所要研究的目的。 基於此，本篇論文以模擬方式及經濟模型加以分析風險基礎資本、情境分析及涉險值等方法的破產預測的相對精確性。其中風險基礎資本完全採用現有NAIC的年報資料，情境分析及涉險值則採用我們所建立的模型，基於此也可以確認現有監理制度是否有缺失。 我們的結果發現風險基礎資本的預測能力很低，動態模型-情境分析及涉險值皆優於風險基礎資本，且在不同動態模型中涉險值的預測能力較好。因此可知被學者所偏好的動態分析模型應是未來保險監理的方向希望藉由本篇提供監理機關一個參考的依據。 / Solvency prediction of insurers has been the focus of insurance regulation. Among the solvency regulation systems, risked-based capital (RBC) is the most important but RBC still has some drawbacks. Thus, the dynamic financial analyses-scenario analysis and Value at Risk have been developed to be the regulation tool. Although, the scholars prefer the dynamic financial analysis, the regulators still want to make sure the accuracy of dynamic financial analysis. That is the purpose of our paper. Therefore, we use the simulation result and the econometric model to analyze the relative effectiveness of RBC, scenario and Value at Risk (VaR). The RBC is from the annual statement and the scenario and VaR come from our simulation model. Our result shows that the RBC has very low explanatory power, the dynamic financial analysis is better than RBC, and VaR outperform scenario analysis. Thus, we conclude that VaR is the way to go for property-casualty insurance regulators.