Abstract
This paper presents expressions for the multivariate normal-exponential and normal-gamma distributions. It then presents properties of these distributions. These include conditional distributions and a new extension to Stein’s lemma. It is also shown that the multivariate normal-gamma and normal-exponential distribution are not in general closed under conditioning, although they are closed under linear transformations. The paper also demonstrates that there are relationships between the extended skew-normal distribution and the normal-gamma and normal-exponential distributions. Specifically, it is shown that certain limiting cases of the extended skew-normal distribution are normal-gamma and normal-exponential. One interpretation of these results is that the normal-exponential distribution may be considered to be an alternative model to the extended skew-normal in some situations. An alternative point of view, however, is that the normal-exponential distribution is redundant since it may be replicated by a suitable extended skew-normal distribution. The theoretical results are supported by an empirical study of stock returns, which includes use of the multivariate distributions for portfolio selection.
Similar content being viewed by others
References
Abramowitz, M., and I. Stegun. 1965. Handbook of mathematical functions. New York, Dover.
Adcock, C. J. 2002. Asset pricing and portfolio selection based on the multivariate skew-student distribution. Multi-Moment Capital Asset Pricing Models and Related Topics Workshop, Paris.
Adcock, C. J. 2004. Capital asset pricing for UK stocks under the multivariate skew-normal distribution. In Skew Elliptical distributions and their applications: A journey beyond normality, ed. M. Genton, 191–204. Boca Raton, Chapman and Hall.
Adcock, C. J. 2005. Exploiting skewness to build an optimal hedge fund with a currency overlay. Eur. J. Finance, 11, 445–462.
Adcock, C. J. 2007. Extensions of Stein’s lemma for the skew-normal distribution. Commun. Stat. Theory Methods, 36, 1661–1672.
Adcock, C. J., 2010. Asset pricing and portfolio selection based on the multivariate extended skew-Student-t distribution. Ann. Operations Res., 176, 221–234.
Adcock, C. J., N. Areal, M. J. R. Armada, M. C. Cortez, B. Oliveira, and F. Silva. 2012. Conditions under which portfolio performance measures are monotonic functions of the Sharpe ratio. University of Miaho, Working paper.
Adcock, C. J., and K. Shutes. 2001. Portfolio selection based on the multivariate-skew normal distribution, In Financial modelling, ed. A. Skulimowski, 167–177. Krakow, Progress & Business Publishers.
Adcock, C. J., and K. Shutes. 2005. An analysis of skewness and skewness persistence in three emerging markets, Emerging Markets Rev., 6, 396–418.
Aigner, D. J., C. K. Lovell, and P. Schmidt. 1977. Formulation and estimation of stochastic production function model. J. of Econometrics, 12, 21–37.
Arnold, B. C., and R. J. Beaver. 2000. Hidden truncation models. Sankhya Ser. A, 62, 22–35.
Azzalini, A. 1985. A class of distributions which includes the normal ones. Scan. J. Stat., 12, 171–178.
Azzalini, A. 1986. Further results on a class of distributions which includes the normal ones. Statistica, 46, 199–208.
Azzalini, A. 2005. The skew-normal distribution and related multivariate families (with discussion by Marc G. Genton and a rejoinder by the author). Scand. J. Stat., 32, 159–200.
Azzalini, A., and A. Capitanio. 2003. Distributions generated by perturbation of symmetry with emphasis on a multivariate skew t distribution. J. R. Stat. Soc. Ser. B, 65, 367–389.
Azzalini, A., and A. Dalla Valle. 1996. The multivariate skew-normal distribution. Biometrika, 83, 715–726.
Badrinath, S. G., and S. Chatterjee. 1988. On measuring skewness and elongation in common stock return distributions. J. Business, 61, 451–472.
Beedles, W. L., 1979. On the asymmetry of market returns, J. Financial Quan. Anal., 14, 653–660.
Bekaert G., C. R. Harvey, C. B. Erb, and T. E. Viskantam. 1998. Distributional characteristics of emerging market returns & asset allocation. J. Portfolio Manage., 24, 102–116.
Branco, M. D., and D. K. Dey. 2001. A general class of multivariate skew-elliptical distributions. J. Multivariate Anal., 79, 99–113.
Chunhachinda, P., K. Dandapani, S. Hamid, and A. J. Prakash. 1997. Portfolio selection and skewness: Evidence from international stock markets. J. Banking Finance, 21, 143–167.
Corns, T. R. A. and S. E. Satchell. 2007. Skew Brownian motion and pricing European options. Eur. J. Finance, 13, 523–544.
Dey, D. K., and J. Liu. 2004. Prior elicitation from expert opinion: An interactive approach. University of Connecticut Division of Biostatistics, Working Paper.
Elal-Oliveroa, D., H. W. Gómez, and F. A. Quintanac. 2009. Bayesian modeling using a class of bimodal skew-elliptical distributions. J. Stat. Plan. Inference, 139, 1484–1492.
Fama, E. 1970. Efficient capital markets: A review of theory and empirical work. J. Finance, 25, 383–417.
Genton, M. 2004. Skew elliptical distributions and their applications: A journey beyond normality. Boca Raton, FL: Chapman and Hall.
Greene, W. H. 1990. A gamma-distributed stochastic frontier model. J. Econometrics, 46, 141–163.
Harvey, C. R., and A. Siddique. 1997. Conditional skewness in asset pricing tests. J. Finance, 55, 1263–1295.
Harvey, C. R., J. C. Leichty, M. W. Leichty, and P. Muller. 2010. Portfolio selection with higher moments. Quant. Finance, 10, 469–485.
Johnson, N., and S. Kotz. 1970. Continuous univariate distributions 1. Boston, Wiley.
Kattumannil, S. K., 2009. On Stein’s identity and its applications. Stat. Probability Lett. 79, 1444–1449.
Kraus, A., and R. H. Litzenberger. 1976. Skewness preference and the valuation of risk assets. J. Finance, 31, 1085–1100.
Landsman, Z., and J. Nešlehová. 2008. Stein’s Lemma for elliptical random vectors. J. Multivariate Anal., 99, 912–927
Liseo, B., and N. Loperfido. 2003. A Bayesian interpretation of the multivariate skew-normal distribution. Stat. Probability Lett., 61(4), 395–401.
Liu, J. S. 1994. Siegel’s formula via Stein’s identities. Stat. and Probability Lett., 21, 247–251.
Samuelson, P. A. 1970. The fundamental application theorem of portfolio analysis in terms of means, variances and higher moments. Rev. Econ. Stud., 37, 537–542.
Shutes, K. 2005. Non-normality in asset pricing—Extensions and applications of the skew-normal distribution. PhD Thesis. University of Sheffield.
Siegel, A. F. 1993. A surprising covariance involving the minimum of multivariate normal variables. J. Am. Stat. Assoc., 88, 77–80.
Simaan, Y. 1993. Portfolio selection and asset pricing—Three parameter framework. Manage. Sci., 39, 568–587.
Stein, C. 1981. Estimation of the mean of a multivariate normal distribution. Ann. Stat., 9, 1135–1151.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Adcock, C.J., Shutes, K. On the Multivariate Extended Skew-Normal, Normal-Exponential, and Normal-Gamma Distributions. J Stat Theory Pract 6, 636–664 (2012). https://doi.org/10.1080/15598608.2012.719799
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1080/15598608.2012.719799