On the mean and variance of the estimated tangency portfolio weights for small samples

التفاصيل البيبلوغرافية
العنوان: On the mean and variance of the estimated tangency portfolio weights for small samples
المؤلفون: Alfelt, Gustav, Mazur, Stepan, 1988
المصدر: Modern Stochastics: Theory and Applications. 9(4):453-482
مصطلحات موضوعية: Tangency portfolio, singular inverse Wishart, Moore–Penrose inverse, reflexive generalized inverse, estimator moments
الوصف: In this paper, a sample estimator of the tangency portfolio (TP) weights is con-sidered. The focus is on the situation where the number of observations is smaller than the number of assets in the portfolio and the returns are i.i.d. normally distributed. Under these assumptions, the sample covariance matrix follows a singular Wishart distribution and, therefore, the regular inverse cannot be taken. In the paper, bounds and approximations for the first two moments of the estimated TP weights are derived, as well as exact results are obtained when the population covariance matrix is equal to the identity matrix, employing the Moore–Penrose inverse. Moreover, exact moments based on the reflexive generalized inverse are provided. The properties of the bounds are investigated in a simulation study, where they are compared to the sample moments. The difference between the moments based on the reflexive generalized inverse and the sample moments based on the Moore–Penrose inverse is also studied.
وصف الملف: print
URL الوصول: https://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-86280
https://doi.org/10.15559/22-VMSTA212
قاعدة البيانات: SwePub
الوصف
تدمد:23516046
DOI:10.15559/22-VMSTA212