Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-24T02:33:52.512Z Has data issue: false hasContentIssue false

A MARKED COX MODEL FOR THE NUMBER OF IBNR CLAIMS: ESTIMATION AND APPLICATION

Published online by Cambridge University Press:  28 May 2019

Andrei L. Badescu*
Affiliation:
Department of Statistical Sciences University of Toronto100 St. George Street Toronto, ON M5S 3G3, Canada E-Mail: [email protected]
Tianle Chen
Affiliation:
Department of Statistical Sciences University of Toronto100 St. George Street Toronto, ON M5S 3G3, Canada E-Mail: [email protected]
X. Sheldon Lin
Affiliation:
Department of Statistical Sciences University of Toronto100 St. George Street Toronto, ON M5S 3G3, Canada E-Mail: [email protected]
Dameng Tang
Affiliation:
Department of Statistical Sciences University of Toronto100 St. George Street Toronto, ON M5S 3G3, Canada E-Mail: [email protected]

Abstract

Incurred but not reported (IBNR) loss reserving is of great importance for Property & Casualty (P&C) insurers. However, the temporal dependence exhibited in the claim arrival process is not reflected in many current loss reserving models, which might affect the accuracy of the IBNR reserve predictions. To overcome this shortcoming, we proposed a marked Cox process and showed its many desirable properties in Badescu et al. (2016).

In this paper, we consider the model estimation and applications. We first present an expectation–maximization (EM) algorithm which guarantees the efficiency of the estimators unlike the moment estimation methods widely used in estimating Cox processes. In addition, the proposed fitting algorithm can be implemented at a reasonable computational cost. We examine the performance of the proposed algorithm through simulation studies. The applicability of the proposed model is tested by fitting it to a real insurance claim data set. Through out-of-sample tests, we find that the proposed model can provide realistic predictive distributions.

Type
Research Article
Copyright
© Astin Bulletin 2019 

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

Ammeter, H. (1948) A generalization of the collective theory of risk in regard to fluctuating basic-probabilities. Scandinavian Actuarial Journal, (12), 171198.Google Scholar
Antonio, K. and Plat, R. (2014) Micro-level stochastic loss reserving for general insurance. Scandinavian Actuarial Journal, (7), 649669.CrossRefGoogle Scholar
Avanzi, B., Wong, B. and Yang, X. (2015) A micro-level claim count model with overdispersion and reporting delays. Insurance: Mathematics and Economics, 71, 114.Google Scholar
Badescu, A. L., Gong, L., Lin, X.S. and Tang, D. (2015) Modeling correlated frequencies with application in operational risk management. The Journal of Operational Risk, 10 (1), 143.CrossRefGoogle Scholar
Badescu, A.L., Lin, X.S. and Tang, D. (2016) A marked Cox model for the number of IBNR claims: theory. Insurance: Mathematics and Economics, 69, 2937.Google Scholar
Cameron, A.C. and Trivedi, P.K. (2013) Regression Analysis of Count Data, Second Edition. New York: Cambridge University Press.CrossRefGoogle Scholar
Charpentier, A. and Pigeon, M. (2016) Macro vs micro methods in non-life claims reserving an econometric perspective. Risks 4 (2), 12.CrossRefGoogle Scholar
Diggle, P.J. (2003) Statistical Analysis of Spatial Point Patterns. New York: Oxford University Press.Google Scholar
England, P.D. and Verrall, R.J. (2002) Stochastic claims reserving in general insurance. British Actuarial Journal, 8 (3), 443518.CrossRefGoogle Scholar
Fan, J. and Li, R. (2001) Variable selection via nonconcave penalized likelihood and its oracle properties. Journal of the American statistical Association, 96 (456), 1348–1360.CrossRefGoogle Scholar
Friedland, J. (2010) Estimating Unpaid Claims Using Basic Techniques. CAS Exam Study Note, Casualty Actuarial Society, Arlington, Virginia.Google Scholar
Guan, Y. (2006) A composite likelihood approach in fitting spatial point process models. Journal of the American Statistical Association, 101 (476), 1502–1512.CrossRefGoogle Scholar
Jin, X. and Frees, E.W.J. (2013) Comparing micro-and macro-Level loss reserving models. Presentation at ARIA. Washington DC.Google Scholar
Lee, S.C. and Lin, X.S. (2010) Modeling and evaluating insurance losses via mixtures of Erlang distributions. North American Actuarial Journal, 14 (1), 107130.CrossRefGoogle Scholar
Liu, H. and Verrall, R. (2009) Predictive distributions for reserves which separate true IBNR and IBNER claims. Astin Bulletin, 39 (01), 3560.CrossRefGoogle Scholar
Mckenzie, E. (1986) Autoregressive moving-average processes with negative-binomial and geometric marginal distributions. Advances in Applied Probability, 18 (3), 679705.CrossRefGoogle Scholar
Mclachlan, G. and Peel, D. (2001) Finite Mixture Models. New York: John Wiley & Sons.Google Scholar
Moller, J., Syversveen, A.R. and Waagepetersen, R.P. (1998) LogGaussian Cox processes. Scandinavian Journal of Statistics, 25 (3), 451482.CrossRefGoogle Scholar
Moller, J. (2003) Shot noise Cox processes. Advances in Applied Probability, 35 (3), 614640.CrossRefGoogle Scholar
Moller, J. and Waagepetersen, R.P. (2003) Statistical Inference and Simulation for Spatial Point Processes. New York: CRC Press.CrossRefGoogle Scholar
Norberg, R. (1993a) Prediction of outstanding liabilities in non-life insurance. Astin Bulletin, 23 (01), 95115.CrossRefGoogle Scholar
Norberg, R. (1993b) Prediction of outstanding liabilities: parameter estimation. Proceedings of the XXIV ASTIN Coll., 255266.Google Scholar
Norberg, R. (1999) Prediction of outstanding liabilities II: model variations and extensions. Astin Bulletin, 23 (2), 213225.Google Scholar
Renshaw, A.E. and Verrall, R.J. (1998) A stochastic model underlying the chain-ladder technique. British Actuarial Journal, 4 (04), 903923.CrossRefGoogle Scholar
Schnieper, R. (1991) Separating true IBNR and IBNER claims. Astin Bulletin, 21 (01), 111127.CrossRefGoogle Scholar
Tanaka, U., Ogata, Y. and Stoyan, D. (2008) Parameter estimation and model selection for Neyman-Scott point processes. Biometrical Journal, 50 (1), 4357.CrossRefGoogle ScholarPubMed
Tijms, H.C. (1994) Stochastic Models: An Algorithmic Approach. New York: John Wiley & Sons Inc.Google Scholar
Verbelen, R., Gong, L., Antonio, K., Badescu, A.L. and Lin, X.S. (2015) Fitting mixtures of Erlangs to censored and truncated data using the EM algorithm. Astin Bulletin, 45 (3), 729758.CrossRefGoogle Scholar
Verbelen, R., Antonio, K., Claseskens, G. and Crevecoueur (2018) An EM algorithm to model the occurrence of events subject to a reporting delay. Technical Report. Leuven, Belgium: K.U. Leuven.Google Scholar
Verdonck, T., Van Wouwe, M. and Dhaene, J. (2009) A robustification of the chain-ladder method. North American Actuarial Journal, 13 (2), 280298.CrossRefGoogle Scholar
Verrall, R., Nielsen, J.P. and Jessen, A.H. (2010) Prediction of RBNS and IBNR claims using claim amounts and claim counts. Astin Bulletin, 40 (02), 871887.Google Scholar
Verrall, R. and Wüthrich, M.V. (2016) Understanding reporting delay in general insurance. Risks, 4 (3), 25.CrossRefGoogle Scholar
Viterbi, A.J. (1967) Error bounds for convolutional codes and an asymptotically optimum decoding algorithm. Information Theory, IEEE Transactions on, 13 (2), 260269.CrossRefGoogle Scholar
Waagepetersen, R. and Guan, Y. (2009) Two-step estimation for inhomogeneous spatial point processes. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 71 (3), 685702.CrossRefGoogle Scholar
Wüthrich, M.V. and Merz, M. (2008) Stochastic Claims Reserving Methods in Insurance, Vol. 435. New York: John Wiley & Sons.Google Scholar
Wüthrich, M.V. and Merz, M. (2015) Stochastic Claims Reserving Manual: Advances in Dynamic Modeling. Available at SSRN.CrossRefGoogle Scholar
Wüthrich, M. (2018) Neural networks applied to chain-ladder reserving. Available at SSRN.CrossRefGoogle Scholar
Zucchini, W. and Macdonald, I.L. (2009) Hidden Markov Models for Time Series: an Introduction Using R. New York: CRC Press.CrossRefGoogle Scholar