Comments on the paper “Bias-adjustment and calibration of jackknife variance estimator in the presence of non-response”

Abstract: presented a bias adjustment to the jackknife variance estimator of in the presence of non-response. In their paper, they obtained a second-order approximation of the bias of the Rao-Sitter variance estimator and then proposed a bias-adjusted estimator based on this approximation. To compare their proposed variance estimator to various other variance estimators, they performed a simulation study and showed that their variance estimator is superior to the Rao-Sitter variance estimator. In fact they showed that the Rao-Sitter variance estimator suffers from severe underestimation. These results contradict those in the literature, which indicate that the Rao-Sitter variance estimator suffers from a positive bias if the sampling fractions are not negligible; see , and . Because of this contradiction, we felt that a further investigation was warranted. In this paper, we attempt to recreate the results of and, in fact, show that their second order approximation to the bias of the Rao-Sitter variance estimator is incorrect and that their simulation results are also questionable. [Copyright &y& Elsevier]