This monograph deals with Introduction, Basic Concepts, Brief Review of Regression Theory. It present the work related to Least Absolute Deviations (LAD) Regression and its estimation theory with and without auto correlated errors. LAD and Least Squares estimation of censored regression model with fixed and marginal effects are also discussed. Further, it contains LAD estimation for linear and nonlinear regression model for truncated and censored data.

This book provides an introduction to the regression models needed, where an outcome variable for a sample is not representative of the population from which a generalized result is sought.