Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-26T23:01:07.888Z Has data issue: false hasContentIssue false

A Row-Wise Stacking of the Runoff Triangle: State Space Alternatives for IBNR Reserve Prediction

Published online by Cambridge University Press:  09 August 2013

Rodrigo Atherino
Affiliation:
JGP Global Gestao de Recursos, Department of Electrical Engineering, Pontifical Catholic University of Rio de Janeiro
Cristiano Fernandes
Affiliation:
Department of Electrical Engineering, Pontifical Catholic University of Rio de Janeiro

Abstract

This work deals with prediction of IBNR reserve under a different data ordering of the non-cumulative runoff triangle. The rows of the triangle are stacked, resulting in a univariate time series with several missing values. Under this ordering, two approaches entirely based on state space models and the Kalman filter are developed, implemented with two real data sets, and compared with two well-established IBNR estimation methods — the chain ladder and an overdispersed Poisson regression model. The remarks from the empirical results are: (i) computational feasibility and efficiency; (ii) accuracy improvement for IBNR prediction; and (iii) flexibility regarding IBNR modeling possibilities.

Type
Research Article
Copyright
Copyright © International Actuarial Association 2010

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

Bornhuetter, R. and Ferguson, R. (1972) The Actuary and IBNR. Proceedings of the Casualty Actuarial Society, 59, 181195.Google Scholar
Box, G., Jenkins, G. and Reinsel, G. (1994) Time Series Analysis, Forecasting and Control. 3rd edition. Holden-Day.Google Scholar
Brockwell, P.J. and Davis, R.A. (1991) Time Series: Theory and Methods. 2nd edition. Springer-Verlag.Google Scholar
Brockwell, P.J. and Davis, R.A. (2002) Introduction to Time Series and Forecasting. Springer.CrossRefGoogle Scholar
Christofides, S. (1990) Regression models based on log-incremental payments. Claims Reserving Manual, Vol. 2. Institute of Actuaries.Google Scholar
de Jong, P. (2004) Forecasting general insurance liabilities. Technical report, Macquarie University. Department of Actuarial Studies Research Paper Series.Google Scholar
de Jong, P. (2006) Forecasting runoff triangles. North American Actuarial Journal, 10(2), 2838.CrossRefGoogle Scholar
de Jong, P. and Zehnwirth, B. (1983) Claims reserving, state-space models and the Kalman filter. Journal of the Institute of Actuaries, 110, 157181.Google Scholar
de Jong, P. and Mackinnon, M. (1988) Covariances for smoothed estimates in state space models. Biometrika, 75(3), 601602.Google Scholar
Doornick, J.A. (2001) Ox 3.0: An Object-Oriented Matrix Programming Language. Timberlake Consultants LTD.Google Scholar
Doray, L.G. (1996) Umvue of the ibnr reserve in a lognormal linear regression model. Insurance: Mathematics and Economics, 18, 4357.Google Scholar
Doucet, A., Freitas, N. and Gordon, N. (2001) Sequential Monte Carlo Methods in Practice. Springer.Google Scholar
Durbin, J. and Koopman, S.J. (2001) Time Series Analysis by State Space Methods. Oxford Statistical Science Series.Google Scholar
Enders, W. (2004) Applied Econometric Time Series. 2nd edition. John Wiley & Sons.Google Scholar
England, P.D. and Verrall, R.J. (2002) Stochastic claims reserving in general insurance. Journal of the Institute of Actuaries, 129, 176.Google Scholar
Hamilton, J.D. (1994) Time Series Analysis. Princeton University Press.Google Scholar
Hart, D., Buchanan, R. and Howe, B. (1996) The Actuarial Practice of General Insurance. Institute of Actuaries of Australia.Google Scholar
Harvey, A.C. (1989) Forecasting, Structural Time Series Models and the Kalman Filter. Cambridge University Press.Google Scholar
Hertig, J. (1985) A statistical approach to the ibnr-reserves in marine insurance. ASTIN Bulletin, 15, 171183.Google Scholar
Johnson, R. and Wichern, D. (2002) Applied Multivariate Statistical Analysis. 5th edition. Prentice Hall.Google Scholar
Koopman, S.J. (1993) Disturbance smoother fo state space models. Biometrika, 80(1), 117126.Google Scholar
Koopman, S.J. (1997) Exact Initial Kalman Filtering and Smoothing for Nonstationary Time Series Models. Journal of the American Statistical Association, 92, 16301638.Google Scholar
Koopman, S.J., Shephard, N. and Doornik, J.A. (2002) SsfPack 3.0 beta02: Statistical algorithms for models in state space. Unpublished paper. Department of Econometrics, Free University, Amsterdam.Google Scholar
Kremer, E. (1982) Ibnr claims and the two-way model of anova. Scandinavian Actuarial Journal.Google Scholar
Mack, T. (1993) Distribution-free calculation of the standard error of chain ladder reserve estimates. ASTIN Bulletin, 23(2), 213225.Google Scholar
Mack, T. (1994a) Which stochastic model is underlying the chain ladder method? Insurance: Mathematics and Economics, 15, 133138.Google Scholar
Mack, T. (1994b) Measuring the variability of chain ladder reserve estimates. Casualty Actuarial Society Spring Forum, 101182.Google Scholar
Migon, H. and Gamerman, D. (1999) Statistical Inference: an Integrated Approach. A Hodder Arnold Publication.Google Scholar
Ntzoufras, I. and Dellaportas, P. (2002) Bayesian Modelling of Outstanding Liabilities Incorporating Claim Count Uncertainty. North American Actuarial Journal, 6(1), 113136.Google Scholar
Renshaw, A.E. (1989) Chain ladder and interactive modelling (claims reserving and glim). Journal of the Institute of Actuaries, 116, 559587.Google Scholar
Renshaw, A.E. and Verrall, R.J. (1998) A stochastic model underlying the chain-ladder technique. British Actuarial Journal, 4(4), 903923.Google Scholar
Schnieper, R. (1991) Separating true ibnr and ibner claims. ASTIN Bulletin, 21(1).Google Scholar
Shumway, R.H. and Stoffer, D.S. (2006) Time Series Analysis and Its Applications (With R Examples). 2nd edition. Springer.Google Scholar
Tanizaki, H. (1996) Nonlinear Filters. 2nd edition. Springer.Google Scholar
Taylor, G. (1986) Claims Reserving in Non-Life Insurance. North-Holland.Google Scholar
Taylor, G. (2000) Loss Reserving: an Actuarial Perspective. Springer.CrossRefGoogle Scholar
Taylor, G. (2003) Loss reserving: Past, present and future. Research Paper no. 109, The University of Melbourne.Google Scholar
Thisted, R.A. (1988) Elements of Statistical Computing: Numerical Computation. Chapman & Hall.Google Scholar
Verrall, R. (1989) State space representation of the chain ladder linear model. Journal of the Institute of Actuaries, 116, 589610.Google Scholar
Verrall, R. (1991) On the estimation of reserves from loglinear models. Insurance: Mathematics and Economics, 10, 7580.Google Scholar
Wright, T. (1990) A stochastic method for claims reserving in general insurance. Journal of the Institute of Actuaries, 117, 677731.Google Scholar