Estimation of the mean of a K-sample U-statistic with missing outcomes and auxiliaries
结局缺失且有辅助变量时 K 样本 U 统计量均值的估计
We propose estimators of the mean of a K‐sample U‐statistic when data on the outcomes of interest are missing in some sampled units and auxiliary variables are available in the entire sample. The proposed estimators exploit the information available in the auxiliaries without requiring assumptions about the joint distribution of the auxiliaries and outcomes. The properties of the proposed estimators are derived as a consequence of general results on efficient semiparametric…