MONETARY UNIT SAMPLING: COMBINING ACCOUNTS FOR SAMPLING TO INCREASE AUDIT EFFICIENCY AND EFFECTIVENESS – WHEN AND HOW

Gary G. Johnson
Ahmed Al Mohsen
Southeast Missouri State University
ABSTRACT
Monetary Unit Sampling (MUS), a statistical sampling technique developed for auditors,
merges the advantages of attributes sampling and variables sampling. There are two MUS
sampling approaches auditors may use. Although sampling by individual account is by far the
most common, the auditor may gather the sample from combined accounts or accounts
collectively when data are available across the accounts of interest, internal controls pertinent to
each account are comparable, and misstatements are expected to occur in relatively the same
proportions in the accounts sampled (Arens, Elder, & Beasley, 2010). This study explores the
efficiency and effectiveness of the collective sampling approach. The findings suggest that auditors
should consider sampling accounts collectively when the tolerable rate of deviation is less than
1.5%.