Computational Challenges of t and Related Copulas
Volume 20, Issue 1 (2022), pp. 95–110
Pub. online: 2 February 2022
Type: Computing In Data Science
Open Access
Received
5 January 2022
5 January 2022
Accepted
6 January 2022
6 January 2022
Published
2 February 2022
2 February 2022
Abstract
The present paper addresses computational and numerical challenges when working with t copulas and their more complicated extensions, the grouped t and skew t copulas. We demonstrate how the R package nvmix can be used to work with these copulas. In particular, we discuss (quasi-)random sampling and fitting. We highlight the difficulties arising from using more complicated models, such as the lack of availability of a joint density function or the lack of an analytical form of the marginal quantile functions, and give possible solutions along with future research ideas.
Supplementary material
Supplementary MaterialThis paper can be reproduced with the R script reproduce.R and the R package nvmix , version 0.0-7.
References
Daul S, De Giorgi E, Lindskog F, McNeil A (2003). The grouped t-copula with an application to credit risk. Available at SSRN: http://dx.doi.org/10.2139/ssrn.1358956.
Hofert M, Hintz E, Lemieux C (2022). nvmix: multivariate normal variance mixtures. R package version 0.0-7, https://CRAN.R-project.org/package=nvmix.
Hofert M, Kojadinovic I, Maechler M, Yan J (2020). copula: multivariate dependence with copulas. R package version 1.0-0, https://CRAN.R-project.org/package=copula.
Hofert M, Lemieux C (2019). qrng: (randomized) quasi-random number generators. R package version 0.0-7, https://CRAN.R-project.org/package=qrng.
Mashal R, Zeevi A (2002). Beyond correlation: extreme co-movements between financial assets. Available at SSRN: http://dx.doi.org/10.2139/ssrn.317122.
Weibel M, Luethi D, Breymann W (2020). ghyp: generalized hyperbolic distributions and its special cases. R package version 1.6.1, https://CRAN.R-project.org/package=ghyp.