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Skew mixture models for loss distributions: a Bayesian approach. (English) Zbl 1285.62027

Summary: The derivation of loss distribution from insurance data is a very interesting research topic but at the same time not an easy task. To find an analytic solution to the loss distribution may be misleading although this approach is frequently adopted in the actuarial literature. Moreover, it is well recognized that the loss distribution is strongly skewed with heavy tails and presents small, medium and large size claims which hardly can be fitted by a single analytic and parametric distribution. Here we propose a finite mixture of skew normal distributions that provides a better characterization of insurance data. We adopt a Bayesian approach to estimate the model, providing the likelihood and the priors for the all unknown parameters; we implement an adaptive Markov Chain Monte Carlo algorithm to approximate the posterior distribution. We apply our approach to a well known Danish fire loss data and relevant risk measures, such as value-at-risk and expected shortfall probability, are evaluated as well.

MSC:

62F15 Bayesian inference
60E05 Probability distributions: general theory
62H30 Classification and discrimination; cluster analysis (statistical aspects)
91B30 Risk theory, insurance (MSC2010)
62P05 Applications of statistics to actuarial sciences and financial mathematics

References:

[1] Ahn, S.; Kim, J. H.T.; Ramaswami, V., A new class of models for heavy tailed distributions in finance and insurance risk, Insurance: Mathematics and Economics, 51, 43-52 (2012) · Zbl 1284.60024
[2] Andrieu, C.; Moulines, É., On the ergodicity properties of some adaptive MCMC algorithms, The Annals of Applied Probability, 16, 1462-1505 (2006) · Zbl 1114.65001
[3] Andrieu, C.; Thoms, J., A tutorial on adaptive MCMC, Statistics and Computing, 18, 343-373 (2008)
[4] Azzalini, A., A class of distributions which includes the Normal ones, Scandinavian Journal of Statistics, 12, 171-178 (1985) · Zbl 0581.62014
[5] Bayes, C. L.; Branco, M. D., Bayesian inference for the skewness parameter of the scalar Skew Normal distribution, Brazilian Journal of Probability and Statistics, 21, 141-163 (2007) · Zbl 1319.62057
[6] Bernardi, M., 2012. Risk measures for Skew-Normal mixtures. MPRA Paper No. 39828.; Bernardi, M., 2012. Risk measures for Skew-Normal mixtures. MPRA Paper No. 39828. · Zbl 1284.62105
[7] Bernardi, M., Petrella, L., 2012. Parallel adaptive MCMC with applications. In: Proceedings of the 46th Italian Statistical Society Meeting.; Bernardi, M., Petrella, L., 2012. Parallel adaptive MCMC with applications. In: Proceedings of the 46th Italian Statistical Society Meeting.
[8] Bernardo, J. M., Reference analysis, (Handbook of Statistics, Vol. 25 (2005), Elsevier, North-Holland: Elsevier, North-Holland Amsterdam), 459-507
[9] Bolance, C.; Guillen, M.; Pelican, E.; Vernic, R., Skewed bivariate models and nonparametric estimation for the CTE risk measure, Insurance: Mathematics and Economics, 43, 386-393 (2008) · Zbl 1156.91023
[10] Burnecki, K.; Misiorek, A.; Weron, R., Loss distributions, (Cizek, P.; Härdle, W. K.; Weron, R., Statistical Tools for Finance and Insurance (2010), Springer-Verlag)
[11] Celeux, G.; Hurn, M. N.; Robert, C. P., Computational and inferential difficulties with mixture posterior distributions, Journal of the American Statistical Association, 95, 957-979 (2000) · Zbl 0999.62020
[12] Chipman, H.; George, E. I.; McCulloch, E., The practical implementation of Bayesian model selection, IMS Lecture Notes—Monograph Series, 38 (2001)
[13] Cooray, K.; Amanda, M. A., Modeling actuarial data with a composite Lognormal Pareto model, Scandinavian Actuarial Journal, 5, 321-334 (2005) · Zbl 1143.91027
[14] Diebold, J.; Robert, C. P., Estimation of finite mixture distributions through Bayesian sampling, Biometrika, 56, 363-375 (1994) · Zbl 0796.62028
[15] Eling, M., Fitting insurance claims to skewed distributions: are the Skew-Normal and Skew-Student good models?, Insurance: Mathematics and Economics, 51, 239-248 (2012)
[16] Embrechts, P.; Klüppelberg, C.; Mikosch, T., Modelling Extremal Events for Insurance and Finance (1997), Springer-Verlag: Springer-Verlag New York · Zbl 0873.62116
[17] Frigessi, A.; Haug, O.; Rue, H., A dynamic mixture model for unsupervised tail estimation without threshold selection, Extremes, 5, 219-235 (2002) · Zbl 1039.62042
[18] Frühwirth-Schnatter, S., (Finite Mixture and Markov Switching Models. Finite Mixture and Markov Switching Models, Springer Series in Statistics (2006), Springer: Springer New York) · Zbl 1108.62002
[19] Frühwirth-Schnatter, S.; Pyne, S., Bayesian inference for finite mixtures of univariate and multivariate Skew-Normal and Skew-\(t\) distributions, Biostatistics, 11, 317-336 (2010) · Zbl 1437.62465
[20] Genton, M. G., Skew-Elliptical Distriutions and their Applications: A Journey Beyond Normality (2004), Chapman and Hall · Zbl 1069.62045
[21] Geweke, J., Evaluating the accuracy of sampling-based approaches to the calculation of posterior moments, (Bernardo, J. M.; Berger, J.; Dawid, A. P.; Smith, A. F.M., Bayesian Statistics, Vol. 4 (1992), Oxford University Press), 169-193
[22] Geweke, J., Contemporary Bayesian Econometrics and Statistics, Wiley Series in Probability and Statistics (2005), Wiley: Wiley Hoboken · Zbl 1093.62107
[23] Haario, H.; Saksman, E.; Tamminen, J., An adaptive Metropolis algorithm, Bernoulli, 14, 223-242 (2001) · Zbl 0989.65004
[24] Hastings, W. K., Monte Carlo sampling methods using Markov chains and their applications, Biometrika, 57, 97-109 (1970) · Zbl 0219.65008
[25] Jasra, A.; Holmes, C. C.; Stephens, D. A., Markov chain Monte Carlo methods and the label switching problem in Bayesian mixture modelling, Statistical Science, 20, 50-67 (2005) · Zbl 1100.62032
[26] Kass, R. E.; Raftery, A. E., Bayes factors, Journal of the American Statistical Association, 90, 773-795 (1995) · Zbl 0846.62028
[27] Lagona, F.; Picone, M., Model-based clustering of multivariate skew data with circular components and missing values, Journal of Applied Statistics, 39, 927-945 (2012) · Zbl 1514.62115
[28] Liseo, B.; Loperfido, M. A., A note on reference priors for the scalar Skew Normal distribution, Journal of Statistical Planning and Inference, 136, 373-389 (2006) · Zbl 1077.62017
[29] Marin, J. M.; Mengersen, K.; Robert, C. P., Bayesian modelling and inference on mixtures of distributions, (Handbook of Statistics, Vol. 25 (2005), Elsevier, North-Holland: Elsevier, North-Holland Amsterdam), 459-507
[30] McNeil, A. J., Estimating the tails of loss severity distributions using extreme value theory, Astin Bulletin, 27, 117-137 (1997)
[31] Metropolis, N.; Rosenbluth, A. W.; Rosenbluth, M. N.; Teller, A. H.; Teller, E., Equations of state calculations by fast computing machines, Journal of Chemical Physics, 21, 1087-1091 (1953) · Zbl 1431.65006
[32] Neal, R. M., Annealed importance sampling, Statistics and Computing, 11, 125-139 (2001)
[33] Richardson, S.; Green, P. J., On Bayesian analysis of mixtures with an unknown number of components, Journal of the Royal Statistical Society. Series B. Statistical Methodology, 59, 731-758 (1997) · Zbl 0891.62020
[34] Robbins, H.; Monro, S., A stochastic approximation method, Annals of Mathematical Statistics, 22, 400-407 (1951) · Zbl 0054.05901
[35] Robert, C. P., Mixtures of distributions: inference and estimation, (Gilks, W. R.; Richardson, S.; Spiegelhalter, D. J., Markov Chain Monte Carlo in Practice (1996), Chapman and Hall) · Zbl 0849.62013
[36] Robert, C. P.; Casella, G., (Monte Carlo Statistical Methods. Monte Carlo Statistical Methods, Springer Texts in Statistics (2004), Springer: Springer New York) · Zbl 1096.62003
[37] Sahu, S. K.; Dey, D. K.; Branco, M. D., A new class of multivariate skew distributions with applications to Bayesian regression models, Canadian Journal of Statistics, 31, 129-150 (2003) · Zbl 1039.62047
[38] Sattayatham, P.; Talangtam, T., Fitting of finite mixture distributions to motor insurance claims, Journal of Mathematics and Statistics, 8, 49-56 (2012)
[39] Scollnik, D. P.M., On composite lognormal-Pareto models, Scandinavian Actuarial Journal, 1, 20-33 (2007) · Zbl 1146.91028
[40] Spiegelhalter, D. J.; Best, N. G.; Carlin, B. P.; van der Linde, A., Bayesian measures of model complexity and fit, Journal of the Royal Statistical Society. Series B. Statistical Methodology, 59, 731-792 (2002)
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