The major reason that the difference and ratio estimation methods would be expected to produce audit efficiency is that the
- Number of members of the populations of differences or ratios is smaller than the number of members of the population of book values.
- Beta risk may be completely ignored.
- Calculations required in using difference or ratio estimation are less arduous and fewer than those required when using direct estimation.
- Variability of the populations of differences or ratios is less than that of the populations of book values or audited values.