Insolvencies Among Automobile Insurers

Two different applications have been considered, automobile claims from Massachusetts and health expenses from the Netherlands. We have fit 11 different distributions to these data. The distributions are conveniently nested within a single four parameter distribution, the generalized beta of the second type. This relationship facilitates analysis and comparisons. In both cases the GB2 provided the best fit and the Burr 3 is the best three parameter model. In the case of automobile claims, the flexibility of the GB2 provides a statistically siE;nificant improvement in fit over all other models. In the case of Dutch health expenses the improvement of the GB2 relative to several alternatives was not statistically significant. * The author appreciates the research assistance of Mark Bean, Young Yong Kim and Steve White. The data used were provided by Richard Derrig of The Massachusetts Automobile Rating and Accident Prevention Bureau and by Bob Van der Laan and The Silver Cross Foundation for the medical insurance claim data. 2~ REFERENCES Arnold, B. C. 1983. Pareto Distributions. Bartonsville: International Cooperative Publishing House. Cummins, J. D. and L. R. Freifelder. 1978. A comparative analysis of alternative maximum probable yearly aggregate loss estimators. Journal of Risk and Insurance 45:27-52. *Cummins, J. D., G. Dionne, and L. Maistre. 1987. Application of the GB2 family of distributions in collective risk theory. University of Pennsylvania: Mimeographed manuscript. Hogg, R. V. and S. A. Klugman. 1983. On the estimation of long tailed skewed distributions with actuarial applications.

The Economics of Property-Casualty Insurance presents new research and findings on key aspects of the economics of the property-casualty insurance industry. The volume explores the industrial organization, regulation, financing, and taxation of this business. The first paper, on external financing and insurance cycles, contains a wealth of information on trends and patterns in the industry's financial structure. The last essay, which compares performance of stock and mutual insurance companies, takes a fresh look at the way a company's organizational structure affects its responses to different economic situations. Two papers focus on rate regulation in the auto insurance industry, and provide broad overviews of the structure and economics of the insurance industry as a whole. Also addressed are the system of regulating insurance companies in the United States, who insures the insurers, and the effects of tax law changes in the 1980s on the prices of insurance policies.