Case-deletion type diagnostics for calibration estimators in survey sampling

Based on the use of calibration techniques as a way of handling nonresponse, case-deletion diagnostics for calibration estimators are proposed. A deleted case is dealt with as it were a nonresponse case. Two types of diagnostics are proposed: one compares the calibration weights and the other compares the estimates. These diagnostics are studied in depth for the general regression estimator, and can be calculated from quantities related to the full data set. They are related to the Cook distance and their similarities and differences are highlighted. Both an artificial and a real example are included as illustrations of the diagnostics proposed.