Sampling variance of a multi-phase stratified design on partially exchangeable sequences
| Main Authors: | Huang, Chun-Kai (Karl), North, Delia, Zewotir, Temesgen |
|---|---|
| Format: | Proceeding |
| Bahasa: | eng |
| Terbitan: |
, 2016
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3358336 |
Daftar Isi:
- In estimating the population mean of a study variable y, we can often use a ratio-type estimator when a related auxiliary variable x, with improved accessibility, is available. In cases where x is qualitative, or may be categorised, and a double sampling plan is used, we may consider a two-phase stratified sampling design. Traditionally, it is assumed that the N variables representing the readings on y are IID within and across strata. In this paper, we relax this assumption to a judgement of exchangeable sequences within each stratum, while still maintaining the assumption of independence across strata. This caters for the existence of dependence structures for within-stratum readings. We propose a methodology for estimating the variance of the ratio estimator under this scenario. Through an example, we show that this method provides a significantly more conservative estimate for the sampling variance, as compared to the standard approach.