In this paper, we propose a new credibility model based on heterogeneous integer-valued self-exciting threshold autoregressive time series, in which the SETINAR(2, 1) process is used to fit the claim numbers of policyholders for consecutive periods, and the unobservable heterogeneity is assumed to follow Gamma distribution. We obtain the Bayesian pricing formula for the proposed model and present some numerical examples to illustrate how the claim history affects the future premiums. We also apply the proposed model to a real panel dataset from the Wisconsin Local Government Property Insurance Fund. By comparing with some existing models, we find that our model can exploit the past information more efficiently and has better predictive performance.
Citation: Shuo Zhang, Jianhua Cheng. Bayesian premium of a credibility model based on a heterogeneous SETINAR(2, 1) process[J]. AIMS Mathematics, 2023, 8(12): 28710-28727. doi: 10.3934/math.20231469
In this paper, we propose a new credibility model based on heterogeneous integer-valued self-exciting threshold autoregressive time series, in which the SETINAR(2, 1) process is used to fit the claim numbers of policyholders for consecutive periods, and the unobservable heterogeneity is assumed to follow Gamma distribution. We obtain the Bayesian pricing formula for the proposed model and present some numerical examples to illustrate how the claim history affects the future premiums. We also apply the proposed model to a real panel dataset from the Wisconsin Local Government Property Insurance Fund. By comparing with some existing models, we find that our model can exploit the past information more efficiently and has better predictive performance.
[1] | J. Lemaire, Bonus-malus systems in automobile insurance, Dordrecht: Kluwer Academic Publisher, 1995. https://doi.org/10.1007/978-94-011-0631-3 |
[2] | H. Bühlmann, G. Alois, A course in credibility theory and its applications, Berlin, Heidelberg: Springer, 2005. https://doi.org/10.1007/3-540-29273-X |
[3] | M. Denuit, X. Maréchal, S. Pitrebois, J. F. Walhin, Actuarial modelling of claim counts: risk classification, credibility and bonus-malus scales, New York: Wiley, 2007. https://doi.org/10.1002/9780470517420 |
[4] | J. Pinquet, Experience rating in non-life insurance, In: G. Dionne, Handbook of insurance, New York: Springer, 2013,471–485. https://doi.org/10.1007/978-1-4614-0155-1_17 |
[5] | J. Pinquet, M. Guillén, C. Bolancé, Allowance for age of claims in bonus-malus systems, ASTIN Bull.: J. IAA, 31 (2001), 337–348. https://doi.org/10.2143/AST.31.2.1009 doi: 10.2143/AST.31.2.1009 |
[6] | N. Brouhns, M. Guillén, M. Denuit, J. Pinquet, Bonus-malus scales in segmented tariffs with stochastic migration between segments, J. Risk Insur., 70 (2003), 577–599. https://doi.org/10.1046/j.0022-4367.2003.00066.x doi: 10.1046/j.0022-4367.2003.00066.x |
[7] | O. Purcaru, M. Guillén, M. Denuit, Linear credibility models based on time series for claim counts, Belg. Actuarial Bull., 4 (2004), 62–74. |
[8] | C. Bolancé, M. Denuit, M. Guillén, P. Lambert, Greatest accuracy credibility with dynamic heterogeneity: the Harvey-Fernandes model, Belg. Actuarial Bull., 7 (2007), 14–18. |
[9] | P. Shi, E. A. Valdez, Longitudinal modeling of insurance claim counts using jitters, Scand. Actuar. J., 2 (2014), 159–179. https://doi.org/10.1080/03461238.2012.670611 doi: 10.1080/03461238.2012.670611 |
[10] | A. Abdallah, J. P. Boucher, H. Cossette, Sarmanov family of multivariate distributions for bivariate dynamic claim counts model, Insur. Math. Econ., 68 (2016), 120–133. https://doi.org/10.1016/j.insmatheco.2016.01.003 doi: 10.1016/j.insmatheco.2016.01.003 |
[11] | C. Gourieroux, J. Jasiak, Heterogeneous INAR(1) model with application to car insurance, Insur. Math. Econ., 34 (2004), 177–192. https://doi.org/10.1016/j.insmatheco.2003.11.005 doi: 10.1016/j.insmatheco.2003.11.005 |
[12] | M. A. Al-Osh, A. A. Alzaid, First-order integer-valued autoregressive INAR(1) process, J. Time Ser. Anal., 8 (1987), 261–275. https://doi.org/10.1111/j.1467-9892.1987.tb00438.x doi: 10.1111/j.1467-9892.1987.tb00438.x |
[13] | L. Bermúdez, M. Guillén, D. Karlis, Allowing for time and cross dependence assumptions between claim counts in ratemaking models, Insur. Math. Econ., 83 (2018), 161–169. https://doi.org/10.1016/j.insmatheco.2018.06.003 doi: 10.1016/j.insmatheco.2018.06.003 |
[14] | L. Bermúdez, D. Karlis, Multivariate INAR(1) regression models based on the Sarmanov distribution, Mathematics, 9 (2021), 505. https://doi.org/10.3390/math9050505 doi: 10.3390/math9050505 |
[15] | P. C. Zhang, Z. Z. Chen, G. Tzougas, E. Calderín-Ojeda, A. Dassios, X. Y. Wu, Multivariate zero-inflated INAR(1) model with an application in automobile insurance, SSRN, 2022. https://doi.org/10.2139/ssrn.4170555 |
[16] | X. Hu, J. Yao, A combined integer-valued autoregressive process with actuarial applications, unpublished paper, 2023. https://doi.org/10.21203/rs.3.rs-2734214/v1 |
[17] | M. Monteiro, M. G. Scotto, I. Pereira, Integer-valued self-exciting threshold autoregressive processes, Commun. Stat.-Theory M., 41 (2012), 2717–2737. https://doi.org/10.1080/03610926.2011.556292 doi: 10.1080/03610926.2011.556292 |
[18] | S. Asmussen, Modeling and performance of bonus-malus systems: stationarity versus age-correction, Risks, 2 (2014), 49–73. https://doi.org/10.3390/risks2010049 doi: 10.3390/risks2010049 |
[19] | E. W. Frees, G. Lee, L. Yang, Multivariate frequency-severity regression models in insurance, Risks, 4 (2016), 4. https://doi.org/10.3390/risks4010004 doi: 10.3390/risks4010004 |
[20] | Z. Y. Quan, E. A. Valdez, Predictive analytics of insurance claims using multivariate decision trees, Depend. Model., 6 (2018), 377–407. |
[21] | R. Oh, S. Peng, J. Y. Ahn, Bonus-malus premiums under the dependent frequency-severity modeling, Scand. Actuar. J., 2020 (2020), 172–195. https://doi.org/10.1080/03461238.2019.1655477 doi: 10.1080/03461238.2019.1655477 |
[22] | R. Oh, J. H. T. Kim, J. Y. Ahn, Designing a bonus-malus system reflecting the claim size under the dependent frequency-severity model, Probab. Eng. Informa. Sci., 36 (2022), 963–987. https://doi.org/10.1017/S0269964821000188 doi: 10.1017/S0269964821000188 |
[23] | Z. Z. Chen, A. Dassios, G. Tzougas, EM estimation for bivariate mixed poisson INAR(1) claim count regression models with correlated random effects, Eur. Actuar. J., 2023. https://doi.org/10.1007/s13385-023-00351-7 |