PMID- 36246856 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20221019 IS - 0266-4763 (Print) IS - 1360-0532 (Electronic) IS - 0266-4763 (Linking) VI - 49 IP - 14 DP - 2022 TI - Shrinkage estimation of fixed and random effects in linear quantile mixed models. PG - 3693-3716 LID - 10.1080/02664763.2021.1962262 [doi] AB - This paper presents a Bayesian analysis of linear mixed models for quantile regression using a modified Cholesky decomposition for the covariance matrix of random effects and an asymmetric Laplace distribution for the error distribution. We consider several novel Bayesian shrinkage approaches for both fixed and random effects in a linear mixed quantile model using extended L1 penalties. To improve mixing of the Markov chains, a simple and efficient partially collapsed Gibbs sampling algorithm is developed for posterior inference. We also extend the framework to a Bayesian mixed expectile model and develop a Metropolis-Hastings acceptance-rejection (MHAR) algorithm using proposal densities based on iteratively weighted least squares estimation. The proposed approach is then illustrated via both simulated and real data examples. Results indicate that the proposed approach performs very well in comparison to the other approaches. CI - (c) 2021 Informa UK Limited, trading as Taylor & Francis Group. FAU - Ji, Yonggang AU - Ji Y AUID- ORCID: 0000-0002-5912-8231 AD - School of Science, Civil Aviation University of China, Tianjin, People's Republic of China. FAU - Shi, Haifang AU - Shi H AUID- ORCID: 0000-0001-9486-9572 AD - School of Science, Civil Aviation University of China, Tianjin, People's Republic of China. LA - eng PT - Journal Article DEP - 20210806 PL - England TA - J Appl Stat JT - Journal of applied statistics JID - 9883455 PMC - PMC9559065 OTO - NOTNLM OT - Cholesky decomposition OT - Metropolis-Hastings acceptance-rejection OT - Quantile mixed regression OT - expectile mixed regression OT - partially collapsed Gibbs sampling COIS- No potential conflict of interest was reported by the author(s). EDAT- 2021/08/06 00:00 MHDA- 2021/08/06 00:01 PMCR- 2022/08/06 CRDT- 2022/10/17 04:39 PHST- 2022/10/17 04:39 [entrez] PHST- 2021/08/06 00:00 [pubmed] PHST- 2021/08/06 00:01 [medline] PHST- 2022/08/06 00:00 [pmc-release] AID - 1962262 [pii] AID - 10.1080/02664763.2021.1962262 [doi] PST - epublish SO - J Appl Stat. 2021 Aug 6;49(14):3693-3716. doi: 10.1080/02664763.2021.1962262. eCollection 2022.