Reinsurance for Catastrophes and Cataclysms

This paper examines the optimal design of insurance and reinsurance policies. We first consider reinsurance for catastrophes: risks which are large for any one insurer but not for the reinsurance market as a whole. Reinsurance for catastrophes is complicated by adverse selection. Optimal reinsurnace in the presence of adverse selection depends critically on the source of information asymmetry. When information on the probability of a loss is private but the magnitude of the loss is public optimal reinsurance employs a deductible-style deductible-style excess-of-loss policy, and when is is private but the proba- bility of a loss is common, optimal reinsurance covers small and large risks, but makes the primary insurer responsible for moderate risks. There is a dramatic divergence between these designs, which suggests that traditional approaches to design may be misguided. We then consider reinsurance for cata- clysms: risks that are so large that a loss can threaten the solvency of re- insurance such as a major earthquake, while others derive from common risks-changes in conditions that affect many individuals-such as the liability revolution or or escalating medical care costs. We