An Empirical Study of the Ratio Estimator and Estimators of its Variance
从六个真实总体中抽取随机样本和非随机样本，比较比率估计量及其五种方差估计量的表现，发现基于预测模型的理论能揭示概率抽样分析中隐藏的关键关系。
Abstract Abstract This paper reports results from an empirical study of the ratio estimator for a finite population total. From each of six real populations, 1,000 simple random samples, 1,000 restricted random samples, and three nonrandom samples of size 32 are drawn. Performance of the ratio estimator and of five estimators of its variance is compared with theoretical results generated using (a) prediction (superpopulation) models and (b) probability sampling distributions. The results, presented graphically, show that theory based on prediction models can reveal relationships that are essential in making inferences, but that are concealed in probability sampling analyses. Key Words: Balanced samplesPredictionRatio estimatorRobustnessSampling theoryVariance estimates