Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-28T01:19:20.422Z Has data issue: false hasContentIssue false

Modeling Dependent Risks with Multivariate Erlang Mixtures

Published online by Cambridge University Press:  09 August 2013

Simon C.K. Lee
Affiliation:
Silen Trading and Consulting Inc., E-Mail: [email protected]

Abstract

In this paper, we introduce a class of multivariate Erlang mixtures and present its desirable properties. We show that a multivariate Erlang mixture could be an ideal multivariate parametric model for insurance modeling, especially when modeling dependence is a concern. When multivariate losses are governed by a multivariate Erlang mixture, many quantities of interest such as joint density and Laplace transform, moments, and Kendall's tau have a closed form. Further, the class is closed under convolutions and mixtures, which enables us to model aggregate losses in a straightforward way. We also introduce a new concept called quasi-comonotonicity that can be useful to derive an upper bound for individual losses in a multivariate stochastic order and upper bounds for stop-loss premiums of the aggregate loss. Finally, an EM algorithm tailored to multivariate Erlang mixtures is presented and numerical experiments are performed to test the efficiency of the algorithm.

Type
Research Article
Copyright
Copyright © International Actuarial Association 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Asmussen, S. and Albrecher, H. (2010) Ruin Probabilities, 2nd Edition, Singapore: World Scientific Publishing.Google Scholar
Asmussen, S., Nerman, O. and Olsson, M. (1996) “Fitting phase-type distributions via the EM algorithm”, Scandinavian Journal of Statistics 23(4), 419441.Google Scholar
Assaf, D., Langberg, N.A., Savits, T.H. and Shaked, M. (1984) “Multivariate phase-type distributions”, Operations Research 32(3), 688702.Google Scholar
Billingsley, P. (1995) Probability and Measure, Third Edition, John Wiley and Sons, Hoboken, NJ.Google Scholar
Dempster, A.P., Laird, N.M. and Rubin, D.B. (1977) “Maximum likelihood from incomplete data via the EM algorithm”, Journal of the Royal Statistical Society, Series B (Methodological), 39(1), 138.Google Scholar
Denuit, M., Dhaene, J., Goovaerts, M.J. and Kaas, R. (2005) Actuarial Theory for Dependent Risks: Measures, Orders and Models. Wiley and Sons.Google Scholar
Dhaene, J., Denuit, M., Goovaerts, M.J., Kaas, R. and Vyncke, D. (2002) “The concept of comonotonicity in actuarial science and finance: theory”, Insurance: Mathematics and Economics, 31, 333.Google Scholar
Dhaene, J., Denuit, M., Goovaerts, M.J., Kaas, R. and Vyncke, D. (2002) “The concept of comonotonicity in actuarial science and finance: applications”, Insurance: Mathematics and Economics, 31, 133161.Google Scholar
Dhaene, J., Vanduffel, S., Tang, Q., Goovaerts, M.J., Kaas, R. and Vyncke, D. (2006) Risk measures and comonotonicity: a review. Stochastic Models, 22, 573606.Google Scholar
Eisele, K-T. (2005) “EM algorithm for bivariate phase distributions”, ASTIN Colloquium, Zurich, Switzerland. http://www.actuaries.org/ASTIN/Colloquia/Zurich/Eisele.pdf Google Scholar
Fréchet, M.R. (1951) “Sur les tableaux de corrélation dont les marges sont données”, Annal University Lyon Science, 4, 5384.Google Scholar
Fréchet, M.R. (1958) “Remarques au sujet de la note précédente”, C. R. Acad. Sci. Paris Sr. I Math., 246, 27192720.Google Scholar
Frees, E.W. and Valdez, E.A. (1998) “Understanding relationships using copulas”, North American Actuarial Journal, 2(1), 125.Google Scholar
Furman, E. and Landsman, Z. (2010) “Multivariate Tweedie distributions and some related capital-at-risk analyses”, Insurance: Mathematics and Economics, 46, 351361.Google Scholar
Genest, C., Gerber, H.U., Goovaerts, M.J. and Laeven, R.J.A. (2009) “Editorial to the special issue on modeling and measurement of multivariate risk in insurance and finance”. Insurance: Mathematics and Economics, 44, 143145.Google Scholar
Hoeffding, W. (1940) “Scale-invariant correlation theory, In N.I. Fisher and P.K. Sen (eds.), The Collected Works of Wassily Hoeffding”, New York: Springer-Verlag.Google Scholar
Hoeffding, W. (1940) “Scale-invariant correlation measures for discontinuous distributions, In N.I. Fisher and P.K. Sen (eds.), The Collected Works of Wassily Hoeffding”, New York: Springer-Verlag.Google Scholar
Joe, H. (1997) Multivariate Models and Dependence Concepts, Chapman and Hall, London.Google Scholar
Johnson, N.L., Kotz, S. and Balakrishnan, A.V. (1997) Discrete Multivariate Distributions. Wiley and Sons.Google Scholar
Li, D.X. (2000) “On default correlation: a copula approach”, Journal of Fixed Income, 9, March, 4354.Google Scholar
Lee, C.K. and Lin, X.S. (2010) “Modeling and Evaluating Insurance Losses via Mixtures of Erlang Distributions”, North American Actuarial Journal, 14(1), 107130.Google Scholar
Lin, X.S. and Tan, K.S. (2003) “Valuation of equity-indexed annuities under stochastic interest rate”, North American Actuarial Journal, 7(4), 7291.Google Scholar
Mikosch, T. (2006) “Copulas: tales and facts”, Extremes, 9, 320.Google Scholar
Nelson, R.B. (1999) An Introduction to Copulas. Lecture Notes in Statistics 139, Springer, New York.Google Scholar
Shaked, M. and Shanthikumar, J.G. (1994) Stochastic Orders and Their Applications. Academic Press, San Diego.Google Scholar
Vanduffel, S., Hoedemakers, T. and Dhaene, J. (2005) “Comparing approximations for risk measures of sums of non-independent lognormal random variables”, North American Actuarial Journal, 9(4), 7182.Google Scholar
Willmot, G.E and Woo, J.K. (2007) “On the class of Erlang mixtures with risk theoretic applications”, North American Actuarial Journal, 11(2), 99115.CrossRefGoogle Scholar