A 2019 analysis by Public Company Accounting Oversight Board (PCAOB) in the United States observed that the big four accounting firms bungled almost 31% of their audits since 2009. In another project study on government oversight, it was seen that while the auditors colluded to present audit reports that pleased their clients, the times they didn't resulted in a loss of business. Despite this large-scale collusion in audits, the PCAOB in its 16-year history has only made 18 enforcement cases against the "big four". Although these auditors have failed audits in 31% of cases (808 cases in total), they have only faced action by PCAOB in 6.6% of the cases. KPMG at that point had never been fined despite having the worst audit failure rate of 36.6%.