The Re-examination Of The "Big Four" Auditors And Audit Quality

Based on the data of A-share listed companies from 2007 to 2015,this paper chooses discretionary accruals,the probability of issuing non-standard unqualified opinions and audit fees as the proxy variables of audit quality.Using Heckman's two-stage regression model and propensity score matching model,this paper re-examines the relations between big four auditors and audit quality.Results using Heckman's two-stage regression model show that a significant self-selection issue is in the presence of auditors and audit quality.Results using propensity score matching show that the matching reduces self-selection problem,the propensity score matching method controls the company's characteristics of the customer in the experimental group and the control group.Different accounting firms corresponding to the two groups of audit quality differences,so as to obtain the experimental results.The study shows that after reducing the self-selection problem in the model:if using discretionary accruals and the probability of issuing the non-standard unqualified audit opinions as audit quality proxies,the "big four" has the significantly higher audit quality than " non-big four";however;if using audit fees as an audit quality proxy,the big four effect is disappearing in the two types of accounting firms.In addition,in order to eliminate the influence of the sensitivity of the propensity score matching model on the experimental results,this paper randomly adjusts the influencing factors in the model design,designs 3000 kinds of different models to compare the difference between the pre-match and the post-match audit quality.The experimental results support the above in conclusion.