TITLE:
Variable Selection for Robust Mixture Regression Model with Skew Scale Mixtures of Normal Distributions
AUTHORS:
Tingzhu Chen, Wanzhou Ye
KEYWORDS:
Robust Mixture Regression Model, Skew Scale Mixtures of Normal Distributions, EM Algorithm, SCAD Penalty
JOURNAL NAME:
Advances in Pure Mathematics,
Vol.12 No.3,
March
7,
2022
ABSTRACT: In this paper, we propose a robust mixture regression model based on the skew scale mixtures of normal distributions (RMR-SSMN) which can accommodate asymmetric, heavy-tailed and contaminated data better. For the variable selection problem, the penalized likelihood approach with a new combined penalty function which balances the SCAD and l2 penalty is proposed. The adjusted EM algorithm is presented to get parameter estimates of RMR-SSMN models at a faster convergence rate. As simulations show, our mixture models are more robust than general FMR models and the new combined penalty function outperforms SCAD for variable selection. Finally, the proposed methodology and algorithm are applied to a real data set and achieve reasonable results.