Missing covariate data in generalized linear mixed models with distribution-free random effects

We consider generalized linear mixed models in which random effects are free of parametric distributions and missing at random data are present in some covariates. To overcome the problem of missing data, we propose two novel methods relying on auxiliary variables: a penalized conditional likelihood...

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Main Authors: Liu, Li, Xiang, Liming
Other Authors: School of Physical and Mathematical Sciences
Format: Journal Article
Language:English
Published: 2019
Subjects:
Online Access:https://hdl.handle.net/10356/105576
http://hdl.handle.net/10220/50235
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author Liu, Li
Xiang, Liming
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Liu, Li
Xiang, Liming
author_sort Liu, Li
collection NTU
description We consider generalized linear mixed models in which random effects are free of parametric distributions and missing at random data are present in some covariates. To overcome the problem of missing data, we propose two novel methods relying on auxiliary variables: a penalized conditional likelihood method when covariates are independent of random effects, and a two-step procedure consisting of a pairwise likelihood for estimating fixed effects in the first step and a penalized conditional likelihood for estimating random effects in the second step while covariates can be related to random effects. Our methods allow a nonparametric structure for the missing covariate data and do not rely on distribution assumptions for random effects, which are not observed in the data, thus providing great flexibility in capturing a board range of the missingness mechanism and behaviors of random effects. We show that the proposed estimators enjoy desirable theoretical properties by relaxing the conditions for a finite number of clusters or finite cluster size imposed in the literature. The finite sample performance of the estimators is assessed through extensive simulations. We illustrate the application of the methods using a longitudinal data set on forest health monitoring.
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spelling ntu-10356/1055762023-02-28T19:44:10Z Missing covariate data in generalized linear mixed models with distribution-free random effects Liu, Li Xiang, Liming School of Physical and Mathematical Sciences Generalized Linear Mixed Model Auxiliary Variable Science::Mathematics We consider generalized linear mixed models in which random effects are free of parametric distributions and missing at random data are present in some covariates. To overcome the problem of missing data, we propose two novel methods relying on auxiliary variables: a penalized conditional likelihood method when covariates are independent of random effects, and a two-step procedure consisting of a pairwise likelihood for estimating fixed effects in the first step and a penalized conditional likelihood for estimating random effects in the second step while covariates can be related to random effects. Our methods allow a nonparametric structure for the missing covariate data and do not rely on distribution assumptions for random effects, which are not observed in the data, thus providing great flexibility in capturing a board range of the missingness mechanism and behaviors of random effects. We show that the proposed estimators enjoy desirable theoretical properties by relaxing the conditions for a finite number of clusters or finite cluster size imposed in the literature. The finite sample performance of the estimators is assessed through extensive simulations. We illustrate the application of the methods using a longitudinal data set on forest health monitoring. MOE (Min. of Education, S’pore) Accepted version 2019-10-23T04:46:56Z 2019-12-06T21:53:49Z 2019-10-23T04:46:56Z 2019-12-06T21:53:49Z 2018 Journal Article Liu, L., & Xiang, L. (2019). Missing covariate data in generalized linear mixed models with distribution-free random effects. Computational Statistics & Data Analysis, 134, 1-16. doi:10.1016/j.csda.2018.10.011 0167-9473 https://hdl.handle.net/10356/105576 http://hdl.handle.net/10220/50235 10.1016/j.csda.2018.10.011 en Computational Statistics & Data Analysis © 2018 Elsevier B.V. All rights reserved. This paper was published in Computational Statistics & Data Analysis and is made available with permission of Elsevier B.V. 35 p. application/pdf
spellingShingle Generalized Linear Mixed Model
Auxiliary Variable
Science::Mathematics
Liu, Li
Xiang, Liming
Missing covariate data in generalized linear mixed models with distribution-free random effects
title Missing covariate data in generalized linear mixed models with distribution-free random effects
title_full Missing covariate data in generalized linear mixed models with distribution-free random effects
title_fullStr Missing covariate data in generalized linear mixed models with distribution-free random effects
title_full_unstemmed Missing covariate data in generalized linear mixed models with distribution-free random effects
title_short Missing covariate data in generalized linear mixed models with distribution-free random effects
title_sort missing covariate data in generalized linear mixed models with distribution free random effects
topic Generalized Linear Mixed Model
Auxiliary Variable
Science::Mathematics
url https://hdl.handle.net/10356/105576
http://hdl.handle.net/10220/50235
work_keys_str_mv AT liuli missingcovariatedataingeneralizedlinearmixedmodelswithdistributionfreerandomeffects
AT xiangliming missingcovariatedataingeneralizedlinearmixedmodelswithdistributionfreerandomeffects