Relative efficiency

[−] Forest inventory

[+] Introduction to forest inventory

[+] Forest mensuration

[+] Introduction to sampling

[+] Plot design

[+] Sampling design

[+] Estimation issues

[+] Planning issues

[+] UNFCCC Implications for Forest Monitoring

[+] Forest Inventory Examples

  Forest Inventory Glossary

If, in a sampling study, we have the choice between different sampling designs or within the same sampling design between different estimators, we wish to apply the most efficient one; that is the one that yields best precision for a given effort. This involves the comparison with alternative estimators or/and other sampling designs:

If \(\hat\theta_1\) and \(\hat\theta_2\) are two unbiased estimators, relative efficiency is simply calculated as the ratio of the error variances of the two estimators.

\[RE=\frac{V(\hat\theta_1)}{V(\hat\theta_2)}\]

It should be observed that this is valid for \(var(\hat\theta)\) and not necessarily for \(\hat {var}(\hat\theta)\); that is, from data of a sampling study we can only estimate the relative efficiency.