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Instrumental weighted variables under heteroscedasticity. Part II – Numerical study

Jan Ámos Víšek (2017)

Kybernetika

Results of a numerical study of the behavior of the instrumental weighted variables estimator – in a competition with two other estimators – are presented. The study was performed under various frameworks (homoscedsticity/heteroscedasticity, several level and types of contamination of data, fulfilled/broken orthogonality condition). At the beginning the optimal values of eligible parameters of estimatros in question were empirically established. It was done under the various sizes of data sets and...

Interval estimation in two way nested unbalanced random model.

R. C. Jain, J. Singh, R. Agrawal (1991)

Trabajos de Estadística

The present paper deals with interval estimation of variance components in two way nested unbalanced random model. Employing a suitable transformation a statistic has been developed and its distribution is well approximated by chi-square. The confidence intervals for variance components and the simultaneous confidence interval for their ratios have been derived.

Intrinsic priors for hypothesis testing in normal regression models.

Elías Moreno, F. Javier Girón, Francisco Torres (2003)

RACSAM

Testing that some regression coefficients are equal to zero is an important problem in many applications. Homoscedasticity is not necessarily a realistic condition in this setting and, as a consequence, no frequentist test there exist. Approximate tests have been proposed. In this paper a Bayesian analysis of this problem is carried out, from a default Bayesian model choice perspective. Explicit expressions for intrinsic priors are provided, and it is shown that the corresponding Bayes factor is...

LAMN property for hidden processes : the case of integrated diffusions

Arnaud Gloter, Emmanuel Gobet (2008)

Annales de l'I.H.P. Probabilités et statistiques

In this paper we prove the Local Asymptotic Mixed Normality (LAMN) property for the statistical model given by the observation of local means of a diffusion process X. Our data are given by ∫01X(s+i)/n dμ(s) for i=0, …, n−1 and the unknown parameter appears in the diffusion coefficient of the process X only. Although the data are neither markovian nor gaussian we can write down, with help of Malliavin calculus, an explicit expression for the log-likelihood of the model, and then study the asymptotic...

L'analyse implicative bayésienne, une méthode pour l'étude des dépendances orientées. II : modèle logique sur un tableau de contingence

Jean-Marc Bernard, Camilo Charron (1996)

Mathématiques et Sciences Humaines

Dans Bernard & Charron (1996), nous avons proposé une nouvelle méthode, l'Analyse Implicative Bayésienne (AIB), pour l'étude des dépendances orientées entre deux variables binaires, méthode qui permet de conclure en terme de quasi-implication entre modalités des variables. Nous étendons ici cette méthode au cas d'un tableau de contingence A × B quelconque avec le problème de la mesure du degré de quasi-adéquation des données à un modèle logique donné. Au niveau descriptif, la méthode repose...

L'analyse implicative bayésienne, une méthode pour l'étude des dépendances orientées. I : données binaires

Jean-Marc Bernard, Camilo Charron (1996)

Mathématiques et Sciences Humaines

La réussite à l'épreuve A implique-t-elle, approximativement, la réussite à l'épreuve B ? Parmi les indices descriptifs proposés pour mesurer de telles dépendances orientées, nous considérons l'indice H de Loevinger, qui s'exprime simplement en termes des taux de liaison entre modalités. A partir de cet indice, nous définissons les notions de quasi-implication, de quasi-équivalence et de quasi-indépendance dans un tableau de contingence 2 x 2. Cependant, les méthodes inductives correspondantes,...

Large deviations for quasi-arithmetically self-normalized random variables

Jean-Marie Aubry, Marguerite Zani (2013)

ESAIM: Probability and Statistics

We introduce a family of convex (concave) functions called sup (inf) of powers, which are used as generator functions for a special type of quasi-arithmetic means. Using these means, we generalize the large deviation result on self-normalized statistics that was obtained in the homogeneous case by [Q.-M. Shao, Self-normalized large deviations. Ann. Probab. 25 (1997) 285–328]. Furthermore, in the homogenous case, we derive the Bahadur exact slope for tests using self-normalized statistics.

Least empirical risk procedures in statistical inference

Wojciech Niemiro (1993)

Applicationes Mathematicae

We consider the empirical risk function Q n ( α ) = 1 n ∑ i = 1 n · f ( α , Z i ) (for iid Z i ’s) under the assumption that f(α,z) is convex with respect to α. Asymptotics of the minimum of Q n ( α ) is investigated. Tests for linear hypotheses are derived. Our results generalize some of those concerning LAD estimators and related tests.

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