Measuring financial information manipulation: An evaluation on manufacturing firms traded in Borsa İstanbul

After Messod D. Beneish developed a model revealing the manipulation of financial information in 1997 and developed the final Beneish model in 1999 by making improvements on this model, the research communities have performed many studies on revealing the manipulation of financial information with a certain accuracy rate with the ease provided by this model. The main purpose of this thesis study is to examine the extent to which the auditor's opinions are issued in parallel with the result obtained by implementing this model, considering that the Beneish model is a model that reveals manipulation and that the auditor's opinions are the only element that financial statement users can rely on. In order to achieve this aim, the Beneish (1999) model has been applied to manufacturing industry companies traded in Borsa İstanbul (BİST). In order to strengthen the result of the study, the implementation was made separately for the years 2018, 2019 and 2020. The results of the implementation were compared with the opinions of the auditors, unlike the studies in this field in the literature. At the same time, audit companies are grouped as ''big four audit companies (Big4)'' and ''other companies'', and thus, the parallelism of the auditor's opinions, which is the output of the audit conducted by Big4 companies and other companies, with the result of the implementation has been made. As a result of this thesis, it is concluded that there is no significant parallelism between the auditor's opinions and the possibility of manipulation revealed by implementing the Beneish Model, but it should be noted that misstatements identified by the auditor that will not affect aıuditor's opinion quantitatively and qualitatively may have arisen as a result of manipulative transactions.