天然災害風險及其對財產保險之影響

Abstract

近年來全球氣候變遷和天然災害對保險業有所影響的觀點，被提出且獲得廣泛的討論。就此，本文旨在深入探討氣候變遷與天然災害風險對財產保險之影響，並依探討結果，對保險業提出一些建議。本文收集國內外相關資料與資訊、建構迴歸模型，而後透過時間序列分析資料並探討分析結果。研究結果發現，全球天然災害發生次數有逐年增加的趨勢，導致被保險人的損失增加。然而，天然災害事件損失的機率分配存在厚尾現象，表示極端天然災害事件造成嚴重損失的機率較常態分配為高。我們也發現，天然災害可能存在個體相關，並有一些關聯結構，導致財產保險業分散風險的能力降低；此外，天然災害風險特徵反映逆向選擇和道德危險的問題，導致財產保險公司面對較大之破產風險，因此財產保險公司應更加重視分析天然災害之可保性和市場失靈問題。現今，雖然國家級天然災害保險制度已於世界易遭受巨災損失之國家或地區推行，但仍面臨上述問題。本文最後建議數種方法來解決這些問題，包括(1)設計差別保險費率以降低逆向選擇；(2)加諸精算過的自負額度，以提高防止損失的誘因而達到減少道德危險的目的；(3)利用再保險來轉移超額風險。

In recent years, the impacts of global climate change and natural disasters have been noticed and discussed extensively. In this study, whether climate change and natural disasters have an impact on the insurability and would cause market failure of property insurance are investigated with a view to providing suggestions to benefit the insurance industry. Collect data and information related to the construction of regression models, then analyze these data and to investigate the results through time series analysis. After the analyses, upward trends along with time are found for both the frequency and damage of natural disasters, resulting in increases in both the overall and insured losses. It is also found that the loss distribution of natural disasters is fat-tailed. The result indicates the probability of natural disasters declines slowly relative to the severity of property loss, and the losses of different natural disasters are correlated with one another. It implies that there is lack of risk diversification in the insurance industry. The above features of risk caused by natural disasters reflect problems of adverse selection and moral hazard, which would result in a high risk of insolvency for an insurer. Therefore, property insurance companies should carefully recognize and study the impact of natural disasters on the insurability and market failure problems of property insurance. Although the national natural disaster insurance schemes have been implemented in a few countries, they still face the above problems. Several means are proposed to solve the problems. They include (1) designing a program of premium discrimination to reduce adverse selection, (2) imposing an actuarial deductible to increase loss prevention incentive and decrease moral hazard, and (3) using the reinsurance mechanism to transfer the excess risk.