This book provides an up-to-date account of the theory and applications of linear models. It can be used as a text for courses in statistics at the graduate level as well as an accompanying text for other courses in which linear models play a part. The authors present a unified theory of inference from linear models and its generalizations with minimal assumptions, not only through least squares theory, but also using alternative methods of estimation and testing based on convex loss functions and general estimating equations. Some of the highlights include: sensitivity analysis and model selection, analysis of incomplete data, analysis of categorical data based on a unified presentation of generalized linear models including GEE- and full likelihood methods for correlated response, an extensive appendix on matrix theory, useful to researchers in econometrics, engineering and optimization theory. For this third edition the text has been extensively revised and contains the latest developments in the area of linear models.