In view of the cumbersome and often intractable numerical integrations required For a Full likelihood analysis, several suggestions have been made recently fur approximate inference in generalized linear mixed models ...
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In view of the cumbersome and often intractable numerical integrations required For a Full likelihood analysis, several suggestions have been made recently fur approximate inference in generalized linear mixed models (GLMMs). Tao closely related approximate methods ale the penalized quasi-likelihood (PQL) method and the marginal quasi-likelihood (MQL) method. The PQL approach generally produces biased estimates Tol the regression effects and the variance component of the random effects. Recently, some corrections have been proposed to remove these biases. Rut the corrections appear. to he satisfactory only when the variance component of the random effects is small. The MQL approach has also been used fur inference in the GLMMs. This approach requires the computations of the joint moments of the clustered observations, up to order Four. But the derivation of these moments are not easy. Consequently, different "working" formulas have been used, especially For the mean and covariance matrix of the observations, which may not lead to desirable estimates. In this: paper. we use a small variance component (of the random effects) approach and develop the MQL estimating equations for the parameters based on the joint moments of order up to four. Thc proposed approach thus avoids the use of the so-called "working" covariance and higher order moment matrices, leading to better estimates for the regression and the overdispersion parameters, in the sense of efficiently in particular. (C) 2001 Academic Press AMS 1991 subject classifications: Primary 62A10;Secondary 62F11 ,62F12.
The authors study the empirical likelihood method for linear regression models. They show that when missing responses are imputed using least squares predictors, the empirical log-likelihood ratio is asymptotically a ...
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The authors study the empirical likelihood method for linear regression models. They show that when missing responses are imputed using least squares predictors, the empirical log-likelihood ratio is asymptotically a weighted sum of chi-square variables with unknown weights. They obtain an adjusted empirical log-likelihood ratio which is asymptotically standard chi-square and hence can be used to construct confidence regions. They also obtain a bootstrap empirical log-likelihood ratio and use its distribution to approximate that of the empirical log-likelihood ratio. A simulation study indicates that the proposed methods are comparable in terms of coverage probabilities and average lengths of confidence intervals, and perform better than a normal approximation based method.
This paper presents a method for Bayesian inference for the regression parameters in a linear model with independent and identically distributed errors that does not require the specification of a parametric family of...
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This paper presents a method for Bayesian inference for the regression parameters in a linear model with independent and identically distributed errors that does not require the specification of a parametric family of densities for the error distribution. This method first selects a nonparametric kernel density estimate of the error distribution which is unimodal and based on the least-squares residuals. Once the error distribution is selected, the. Metropolis algorithm is used to obtain the marginal posterior distribution of the regression parameters. The methodology is illustrated with data sets, and its performance relative to standard Bayesian techniques is evaluated using simulation results.
How to Analyze Time-Series Cross-Section Data in the Social Sciences. In this paper we present, step by step, a SAS statistical program for the analysis of Time-Series Cross-Section (TSCS) data which gives robust and ...
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Consider a family of distributions which is invariant under a group of transformations. In this paper, we define an optimality criterion with respect to an arbitrary convex loss function and we prove a characterizatio...
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Consider a family of distributions which is invariant under a group of transformations. In this paper, we define an optimality criterion with respect to an arbitrary convex loss function and we prove a characterization theorem for an equivariant estimator to be optimal. Then we consider a linear model Y = X beta + epsilon, in which epsilon has a multivariate distribution with mean vector zero and has a density belonging to a scale family with scale parameter sigma. Also we assume that the underlying Family of distributions is invariant with respect to a certain group of transformations. First, we find the class of all equivariant estimators of regression parameters and the powers of sigma. By using the characterization theorem we discuss the simultaneous equivariant estimation of the parameters of the linear model.
Classes of semiparametric models, generalizing the proportional and additive hazards, proportional odds and other models are considered. Asymptotical properties of estimators of regression parameters and baseline surv...
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Classes of semiparametric models, generalizing the proportional and additive hazards, proportional odds and other models are considered. Asymptotical properties of estimators of regression parameters and baseline survival function are investigated in the case of one of considered classes.
Recently exponential family based random effects models have received considerable attention. These models usually arise from an unobservable random process added to the independent exponential family models. An unobs...
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Industrial processes may be continuously monitored by instruments under control of microprocessors. Thus the data are usually obtained in the form of sets of (continuous) curves over certain time intervals. This paper...
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Industrial processes may be continuously monitored by instruments under control of microprocessors. Thus the data are usually obtained in the form of sets of (continuous) curves over certain time intervals. This paper presents a method of estimating regression parameters in terms of the sample paths from independent stochastic processes. Time integrated least squares estimators of the parameters are obtained which are unbiased, translation invariant, consistent and asymptotically jointly normal. Since technically it is difficult to compute these estimators, using analog-to-digital conversion of continuous processes which are time sampled at regular intervals, optimal approximations of the estimators are considered which are very easily computable and their asymptotic properties are appended.
The paper considers estimation of p(>3) linear regression parameters (including the mean) under sequential sampling in a Gauss-Markoff setup. A class of James-Stein estimators that dominates the least squares estim...
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The paper considers the estimation of the slope parameter βЄRK for k > 3, in a general linear model. A class of James-Stein estimators is proposed and is compared with the least squares estimator under an appropri...
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