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A nonparametric Bayesian approach to copula estimation. (English) Zbl 07192593

Summary: We propose a novel Dirichlet-based Pólya tree (D-P tree) prior on the copula and based on the D-P tree prior, a nonparametric Bayesian inference procedure. Through theoretical analysis and simulations, we are able to show that the flexibility of the D-P tree prior ensures its consistency in copula estimation, thus able to detect more subtle and complex copula structures than earlier nonparametric Bayesian models, such as a Gaussian copula mixture. Furthermore, the continuity of the imposed D-P tree prior leads to a more favourable smoothing effect in copula estimation over classic frequentist methods, especially with small sets of observations. We also apply our method to the copula prediction between the S&P 500 index and the IBM stock prices during the 2007–08 financial crisis, finding that D-P tree-based methods enjoy strong robustness and flexibility over classic methods under such irregular market behaviours.

MSC:

62G99 Nonparametric inference
62G07 Density estimation
62H20 Measures of association (correlation, canonical correlation, etc.)
62H99 Multivariate analysis
62P05 Applications of statistics to actuarial sciences and financial mathematics

References:

[1] Sklar A. Fonctions de répartition à n dimensions et leurs marges [N-dimensional distribution functions and their margins]. Paris (France): Université Paris 8; 1959. [Google Scholar] · Zbl 0100.14202
[2] Nelsen RB. An introduction to copulas. New York (NY): Springer; 2007. [Google Scholar] · Zbl 1152.62030
[3] Wu J, Wang X, Walker SG.Bayesian nonparametric inference for a multivariate copula function. Methodol Comput Appl Probab. 2014;16(3):747-763. doi: 10.1007/s11009-013-9348-5[Crossref], [Web of Science ®], [Google Scholar] · Zbl 1305.62211
[4] Wu J, Wang X, Walker SG.Bayesian nonparametric estimation of a copula. J Stat Comput Simul. 2015;85(1):103-116. doi: 10.1080/00949655.2013.806508[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 1457.62161
[5] Joe H. Multivariate models and multivariate dependence concepts. Boca Raton (FL): CRC Press; 1997. [Crossref], [Google Scholar] · Zbl 0990.62517
[6] Jaworski P, Durante F, Hardle WK, et al. Copula theory and its applications. Heidelberg: Springer; 2010. [Crossref], [Google Scholar] · Zbl 1194.62077
[7] Chen SX, Huang T-M.Nonparametric estimation of copula functions for dependence modelling. Canad J Statist. 2007;35(2):265-282. doi: 10.1002/cjs.5550350205[Crossref], [Web of Science ®], [Google Scholar] · Zbl 1129.62023
[8] Oakes D.A model for association in bivariate survival data. J R Stat Soc Ser B. 1982;44(3):414-422. [Google Scholar] · Zbl 0503.62035
[9] Oakes D.Semiparametric inference in a model for association in bivariate survival data. Biometrika. 1986;73(2):353-361. [Web of Science ®], [Google Scholar] · Zbl 0604.62035
[10] Genest C, Ghoudi K, Rivest LP.A semiparametric estimation procedure of dependence parameters in multivariate families of distributions. Biometrika. 1995;82(3):543-552. doi: 10.1093/biomet/82.3.543[Crossref], [Web of Science ®], [Google Scholar] · Zbl 0831.62030
[11] Smith MS, Khaled MA.Estimation of copula models with discrete margins via Bayesian data augmentation. J Am Stat Assoc. 2012;107(497):290-303. doi: 10.1080/01621459.2011.644501[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 1261.62051
[12] Smith MS.Bayesian approaches to copula modelling. In: Damien P, Dellaportas PG, Polson N, et al., editors. Bayesian theory and applications. Oxford: Oxford University Press; 2013. p. 336-358. [Crossref], [Google Scholar] · Zbl 1277.62082
[13] Min A, Czado C.Bayesian inference for multivariate copulas using pair-copula constructions. J Financ Econom. 2010;8(4):511-546. doi: 10.1093/jjfinec/nbp031[Crossref], [Web of Science ®], [Google Scholar]
[14] Min A, Czado C.Bayesian model selection for D-vine pair-copula constructions. Canad J Statist. 2011;39(2):239-258. doi: 10.1002/cjs.10098[Crossref], [Web of Science ®], [Google Scholar] · Zbl 1219.62048
[15] Schweizer B, Wolff EF.On nonparametric measures of dependence for random variables. Ann Statist. 1981;9(4):879-885. doi: 10.1214/aos/1176345528[Crossref], [Web of Science ®], [Google Scholar] · Zbl 0468.62012
[16] Deheuvels P.La fonction de dépendance empirique et ses propriétés. un test non paramétrique d’indépendance [The empirical dependency function and its properties. A nonparametric independence test]. Acad Roy Belg Bull Cl Sci (6). 1979;65(6):274-292. [Google Scholar] · Zbl 0422.62037
[17] Scaillet O, Charpentier A, Fermanian JD.The estimation of copulas: theory and practice. In: Rank J, editor. Copulas: from theory to applications in finance. London: Risk Books; 2007. p. 35-62. [Google Scholar]
[18] Behnen K, Hušková M, Neuhaus G.Rank estimators of scores for testing independence. Stat Risk Model. 1985;3(3-4):239-262. [Google Scholar] · Zbl 0606.62045
[19] Gijbels I, Mielniczuk J.Estimating the density of a copula function. Commun Statist Theory Methods. 1990;19(2):445-464. doi: 10.1080/03610929008830212[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 0900.62188
[20] Schuster EF.Incorporating support constraints into nonparametric estimators of densities. Comm Statist Theory Methods. 1985;14(5):1123-1136. doi: 10.1080/03610928508828965[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 0585.62070
[21] Hominal P, Deheuvels P.Estimation non paramétrique de la densité compte-tenu d’informations sur le support [Non-parametric density estimation given support information]. Revue de Statistique Appliquée. 1979;27(3):47-68. [Google Scholar]
[22] Devroye L, Györfi L. Nonparametric density estimation: the l1 view. New York (NY): Wiley; 1985. (Wiley Series in Probability and Statistics;119). [Google Scholar] · Zbl 0546.62015
[23] Gasser T, Müller HG.Kernel Estimation of Regression Functions. In: Gasser, T, Rosenblatt M, editors. Smoothing techniques for curve estimation. Heidelberg: Springer; 1979. p. 23-68. [Crossref], [Google Scholar] · Zbl 0418.62033
[24] John R.Boundary modification for kernel regression. Comm Statist Theory Methods. 1984;13(7):893-900. doi: 10.1080/03610928408828728[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 0552.62022
[25] Müller HG.Smooth optimum kernel estimators near endpoints. Biometrika. 1991;78(3):521-530. doi: 10.1093/biomet/78.3.521[Crossref], [Web of Science ®], [Google Scholar] · Zbl 1192.62108
[26] Dalla Valle L, Leisen F, Rossini L. Bayesian nonparametric estimation of a conditional copula density function. arXiv preprint arXiv:160303484. 2016 [Cited 2017 Jun 27]. [Google Scholar]
[27] Levi E, Craiu RV. Gaussian process single index models for conditional copulas. arXiv preprint arXiv:160303028. 2016 [Cited 2017 Jun 27]. [Google Scholar] · Zbl 1469.62099
[28] Ferguson TS.Prior distributions on spaces of probability measures. Ann Statist. 1974;2(4):615-629. doi: 10.1214/aos/1176342752[Crossref], [Web of Science ®], [Google Scholar] · Zbl 0286.62008
[29] Lavine M.Some aspects of Pólya tree distributions for statistical modelling. Ann Statist. 1992;20(3):1222-1235. doi: 10.1214/aos/1176348767[Crossref], [Web of Science ®], [Google Scholar] · Zbl 0765.62005
[30] Hanson TE.Inference for mixtures of finite Pólya tree models. J Am Stat Assoc. 2006;101(476):1548-1565. doi: 10.1198/016214506000000384[Taylor & Francis Online], [Web of Science ®], [Google Scholar] · Zbl 1171.62323
[31] Paddock SM, Ruggeri F, Lavine M, et al. Randomized Pólya tree models for nonparametric Bayesian inference. Stat Sin. 2003;13(2):443-460. [Web of Science ®], [Google Scholar] · Zbl 1015.62051
[32] Wong WH, Ma L.Optional Pólya tree and Bayesian inference. Ann Statist. 2010;38(3):1433-1459. doi: 10.1214/09-AOS755[Crossref], [Web of Science ®], [Google Scholar] · Zbl 1189.62048
[33] Trippa L, Müller P, Johnson W.The multivariate beta process and an extension of the Pólya tree model. Biometrika. 2011;98(1):17-34. doi: 10.1093/biomet/asq072[Crossref], [PubMed], [Web of Science ®], [Google Scholar] · Zbl 1214.62101
[34] Filippi S, Holmes CC. A Bayesian nonparametric approach to testing for dependence between random variables. Bayesian Analysis. 2017 [Cited 2017 Jun 27]. [Google Scholar] · Zbl 1384.62146
[35] Dortet-Bernadet JL. Bayesian inference on copulas and tests of independence. 2005 [Cited 2017 Jun 27]; unpublished manuscript. [Google Scholar]
[36] Castillo I. Pólya tree posterior distributions on densities. 2016; unpublished manuscript. [Google Scholar] · Zbl 1384.62156
[37] Schervish MJ. Theory of statistics. New York (NY): Springer; 1995. [Crossref], [Google Scholar] · Zbl 0834.62002
[38] Azzalini A, Capitanio A.Statistical applications of the multivariate skew normal distribution. J R Stat Soc Ser B. 1999;61(3):579-602. doi: 10.1111/1467-9868.00194[Crossref], [Google Scholar] · Zbl 0924.62050
[39] Silverman BW. Density estimation for statistics and data analysis, Vol. 26. Boca Raton (FL): CRC press; 1986. [Crossref], [Google Scholar] · Zbl 0617.62042
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