Mixture model, Kernel density estimation, mixture model, Linear regression; mixed models, multiple imputation, quantile regression, Economics, Statistics & Probability, Statistics, Computation Theory and Mathematics, Semi-parametric model, semi-parametric model, Mathematical Sciences, Multiple imputation, Quantile regression, Econometrics, Nonparametric regression and quantile regression, Robustness and adaptive procedures (parametric inference), kernel density estimation, Computational methods for problems pertaining to statistics, EM algorithm