The recent financial crisis has revealed significant externalities and systemic risks that arise from the interconnectedness of financial intermediaries' risk portfolios. We develop a model in which the negative externality arises because intermediaries' actions to diversify that are optimal for...

We study multiline insurance companies with limited liability. Insurance premiums are determined by no-arbitrage principles. The results are developed under the realistic assumption that the losses created by insurer default are allocated among policyholders following an "ex post", pro rata,...

Recent results in value at risk analysis show that, for extremely heavy-tailed risks with unbounded distribution support, diversification may increase value at risk, and that generally it is difficult to construct an appropriate risk measure for such distributions. We further analyze the...

This paper analyzes portfolio diversification for nonlinear transformations of heavy-tailed risks. It is shown that diversification of a portfolio of convex functions of heavy-tailed risks increases the portfolio’s riskiness if expectations of these risks are infinite. In contrast, for...

We develop a framework for the optimal bundling problem of a multiproduct monopolist, who provides goods to consumers with private valuations that are random draws from a distribution with heavy tails. We show that in the Vickrey auction setting, the buyers prefer separate provision of the goods...

Economics

Economics

We develop a model for markets for catastrophic risk. The model explains why insurance providers may choose not to offer insurance for catastrophic risks and not to participate in reinsurance markets, even though there is a large enough market capacity to reach full risk sharing through...

This paper analyzes portfolio diversification for nonlinear transformations of heavy-tailed risks. It is shown that diversification of a portfolio of convex functions of heavy-tailed risks increases the portfolio's riskiness if expectations of these risks are infinite. In contrast, for concave...