The findings of theoretical investigations indicate that short-term auditor tenures may contribute to further audit report lags (ARLs). On the other hand, auditor industry expertise represents one of the determinant factors contributing to audit quality, which has been widely studied in numerous researches. Indeed, the better the quality of audit, the less delayed would be the audit report. As such, aiming at investigating the association between auditor tenure and ARL on the one hand, and studying the adjusting effect of auditor industry expertise on the other hand, the present research investigated 141 firms operating within 25 industries during 2010-2014. Chaw and Hausman Test results indicated, at 5% level of significance, that the corresponding regression model should be assessed with consistent effects. Furthermore, undertaking multivariate linear regression analysis, the research results implied no significance association between auditor tenure and ARL. In fact, the first hypothesis that auditor tenure is negatively related to ARL was rejected. On the other hand, the second hypothesis that auditor industry expertise may attenuate the association of auditor tenure and ARL was also rejected, meaning that, even with auditor industry expertise considered, a significant relationship between auditor tenure and audit report lag could not be recognized.

The purpose of this study is to perform a meta-analysis of the relationship between auditor characteristics and profit quality. In order to integrate the results of different researches and identify the factors that modulate the relationships between auditor characteristics and profit quality, in this research we will use meta-analysis methodology which is one of the quantitative statistical methods. In order to implement the meta-analysis method, they were identified and collected from the websites of foreign journals (articles published in the period 2005 to 2020) and the Internet site of domestic scientific research journals (articles published during the years 2006 to 2021) as a statistical population of the research. Systematic removal has finally analyzed 50 studies; The results of studies conducted in the period and around this relationship indicate that most of these studies are heterogeneous. In order to identify the cause of this heterogeneity, by dividing the research based on different criteria for measuring profit quality and auditor characteristics and calculating intra-group chi-square statistics, we found that these different measurement criteria used in research are one of the factors of contradiction in the results. There have been researches. In the following study, it was observed that there is no significant relationship between auditor characteristics with profit smoothing and timely profit and also between non-audit services provided by the auditor and profit quality, while in contrast, there is no significant relationship between auditor characteristics and quality of accruals; Profit stability; There is the ability to predict profit and conservatism.

Prior researches suggest that auditor specialization and auditor tenure increase audit quality and consequently improve quality of disclosed information and decrease information asymmetry. So the purpose of this paper is to examine the relationship between a company's bid-ask spread, as a proxy of information asymmetry, and auditor tenure and specialization from 2002 to 2010 in the companies listed in Tehran Stock Exchange. Using regression analysis, the findings revealed that there is a negative and statistically significant relationship between auditor tenure and auditor specialization with information asymmetry. In other words auditor specialization and high auditor tenure decrease information asymmetry. In addition separating auditor tenure into short, medium and long periods confirmed the results too. Also the results show that the relationship between auditor tenure and information asymmetry is not influenced by selection of specialists or non-specialists.

One of the strategies of audited firms' management is to divert the auditor's attention from the managed accounts to clean accounts (without misstatement) or accounts that contain misstatements other than managed accounts to affect the auditor's ability to detect fraud. The experimental method and a sample include 106 auditors in 2022. We examine whether managers attempt to reduce the perceived intentionality of their fraudulent misstatements by perpetrating fraud via omission, as opposed to a more active form of commission, and how auditors evaluate the resulting misstatements. We find that managers choose to omit a transaction from the financial statements rather than record a transaction inappropriately. They also decide to omit critical information from supporting documents rather than provide misleading information. However, auditors generally believe that misstatements involving omissions are unintentional. Specifically, we find that auditors are less skeptical of an omitted transaction than a misrecorded transaction. They are also less skeptical of a misstatement that results from management omitting information from a supporting document than misrepresenting information. Finally, a method of fraud (omission) is identified that those managers are likely to use,on the other hand, those auditors are unlikely to judge it as intentional.

In Iran, according to "the rule of the trustworthy audit firms of the stock and exchange organization (2007)", after 4 years of audit services, audit firms are not allowed to accept the position of the CPA of the listed companies. The purpose of legislators is to increase the independence of auditors, because they believe the independence of auditors will be decreased in long auditor tenure. This subject was attractive for Researchers to study the effect of auditor tenure on the accounting conservatism to know what will happen in a long tenure. We also test the effect of the auditor type (Audit Organization or other Firms) on the conservatism Index and we used the model of Givoly and Hayn (2000) to measure the conservatism. The statistical society includes the listed companies in Tehran Stock Exchange from 2003 to 2010. The result of the study indicated that, there is a positive significant relationship between auditor tenure and accounting conservatism, in our opinion, mandatory auditor rotation does not help to increase the accounting conservatism, and therefore we feel the necessity of the revision in the law of mandatory auditor rotation. On the other hand we found that the relationship between auditor types and accounting conservatism is not significant and it means there is no significant difference in accounting conservatism between audit organization and other firms.

Every investor pays special attention to the main factor in their decisions: a return. What is essential for users of financial information is not the procedures and principles used in accounting, but the exit from the financial system, because it helps them achieve their goals. Many capital market concerns focus on accounting and auditing operations. Therefore, the auditor's independence is the basis of public trust in the audit process and the assurance of auditors` reports. For this purpose, this study investigates the effect of auditor switching on abnormal returns. Therefore, three hypotheses have been formulated, and a sample consisting of 365 companies listed on the Tehran Stock Exchange during the years 2010 to 2020 has been selected. The results indicate that auditor switching has no significant effect on abnormal returns. Also, between the CU switch and CD switch, the CD switch has a negative and significant effect on abnormal returns.