Materiality: An Inter-Industry Comparison of the Magnitudes and Stabilities of Various Quantitative Measures.

This article presents and analyzes the results of an inter-industry study on magnitude and stabilities of quantitative measures used by auditors to determine materiality levels during the planning of audits. In this study, relative levels of calculated materiality amounts, determined by using ten different rules of thumb, were compared within and among industries. The authors summarize those rules of thumb which have been suggested as materiality calculations, and estimate and compare the magnitudes and variabilities that result from their use. Their approach used industry data to compare the levels obtained using the various rules of thumb. Specifically, data for 330 companies representing 25 diverse industries were obtained from Standard and Poor's annual Compustat data base. The objective was to apply the various rules of thumb to "real world" data to identify the differences in sizes and stabilities of the resulting measures. Results of this study show that among the various rules of thumb for calculating materiality, sizable differences can occur depending upon the method and the industry.