- Often the sampling frame gives us extra information about each unit that can be used to improve precision of estimates
Ratio Estimation
- For ratio estimation to apply, 2 quantities y and x must be measured on each sample unit
- X auxiliary / subsidiary variable
- Why use ratio estimation
o Sometimes we want to estimate a ratio
§ Average yield of crop
o Want to estimate population total, but population size N is unknown
o Increase precison of estimated means and totals
o Adjust estimates from sample so they reflect demographic totals
o Adjust for non response
Regression Estimation
- Ratio estimation works best if data are well fit by a straight line thru origin
- Difference estimation
o Used in auditing
Estimation in Domains
Models for ratio and Regression Estimation
- Differences between model based and design based estimates
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