Search Results
                                                                                    Working Paper
                                                                                
                                            A New Tool for Robust Estimation and Identification of Unusual Data Points
                                        
                                        
                                        
                                        
                                                                                    
                                                                                                    Most consistent estimators are what Müller (2007) terms “highly fragile”: prone to total breakdown in the presence of a handful of unusual data points. This compromises inference. Robust estimation is a (seldom-used) solution, but commonly used methods have drawbacks. In this paper, building on methods that are relatively unknown in economics, we provide a new tool for robust estimates of mean and covariance, useful both for robust estimation and for detection of unusual data points. It is relatively fast and useful for large data sets. Our performance testing indicates that our baseline ...