決定自留額是保險人承接業務時之主要考量因素，以發揮保險之基本原理原則：危險分散與損失分攤。自留額釐定不當，不僅影響保險人財務結構，甚至波及公司整體核保營運成果而危及清償能力。本文選擇某產險公司實際損失分配資料，探討不同自留比例與再保方式對營運結果之影響，結果顯示在此實際損失分配資料模型下，適度調高自留比例，應可增加核保利潤。本文進一步以相關性分析探討自留配置。 / Retention is a key element for the insurer to determine how much it wishes to retain for its own account for the risks it has written. This point is fundamental to carrying on the business of insurance and akin to the principle upon which insurance is based, namely the spreading of risks and sharing of losses. The risk of incurring a retained loss owning to inadequate retention, which would imperil financial objective even can affect the overall underwriting results and arise insolvency. This paper select data base of occurred loss distribution for the past three years to study the impact of different retained ratio and different type of reinsurance for performance. This paper shows that, the underwriting profit can be expected to increase when the retention increases precisely under the existing loss distribution model . This paper also discuss the related factors in deciding retention by correlation analysis.

傳統的保險人在面對保險契約所承保的風險時，常會藉由國際上的再保險市場來分散其保險風險。由於所承保險事件的不確定性，保險人需要謹慎小心評估其保險風險並將承保風險轉移至再保險人。再保險有兩種主要的保險型式，可區分成比例再保契約及超額損失再保契約，保險人將利用這些再保險契約來分散求償給付時的損失，加強保險人本身的財務清償能力。 本研究，主要在於建構未來損失求償幅度或頻率的預測分佈並模擬未來支付求償的損失。簡單重點重複抽樣法是一種從危險參數的驗後分佈中抽樣的抽樣方法。然而，蒙地卡羅模擬是一種利用大量電腦運算計算近似預測分佈的逼近方法。利用被選取危險參數的驗前分佈來模擬其驗後分佈，並建構可能的承保危險參數結構，將基於馬可夫鏈蒙地卡羅理論的吉普生抽樣方法決定最適自留額，同時運用於再保險合約決策擬定過程。 最後，考慮於不同的再保險契約下來衡量再保險人的自負財務風險。基本上我們研究的對象是針對保險人所承保的風險，再藉由上述的方法來模擬、近似以量化所衍生的財務風險。這將有助於保險人清楚地瞭解其承保的風險，並對其承保業務做妥善的財務風險管理。本研究提供保險人具體的模型建構方法並對此建構技巧做詳細說明及實證分析。 / Insurers traditionally transfer their insurance risk through the international reinsurance market. Due to the uncertainty of these insured risks, the primary insurer need to carefully evaluate the insured risk and further transfer these risks to his ceding reinsurers. There are two major types of reinsurance, i.e. pro rata treaty and excess of loss treaty, used in protecting the claim losses. In this article, the predictive distribution of the claim size is constructed to monitor the future claim underwriting losses based on the reinsurance agreement. Simple Importance Resampling (SIR) are employed in sampling the posterior distribution of risk parameters. Then Monte Carlo simulations are used to approximate the predictive distribution. Plausible prior distributions of these risk parameters are chosen in simulation its posterior distribution. Markov chain Monte Carlo (MCMC) method using Gibbs sampling scheme is also performed based on possible parametric structures. Both the pro rata and excess of loss treaties are investigated to quantify the retention risks of the ceding reinsurers. The insurance risks are focused in our model. Through the implemented model and simulation techniques, it is beneficial for the primary insurer in projecting his underwriting risks. The results show a significant advantage and flexibility using this approach in risk management. This article outlines the procedure of building the model. Finally a practical case study is performed for numerical illustrated.