Tax Revenue (US$ bn) Consulting & Advisory Revenue (US$ bn) Criticism Audit quality and ethics 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%. As per the Financial Reporting Council (FRC) none of the Big Four – Deloitte, EY, KPMG, and PwC managed to surpass the 90% target of its audits. The inefficiency in audit was resulting in a loss of investors' money, people's pension plans, stakeholders' livelihoods and was putting a question mark on the credibility of audited financial statements. "At a time when the future of the audit sector is under the microscope, the latest audit quality results are not acceptable," said Stephen Haddrill, the FRC's Chief executive. Multiple ethics scandals and questionable practices across the globe led to multi-million dollar fines and subsequent settlements by all the Big Four firms. Despite repeated sanctions from regulators, the Big Four have seen continued challenges to audit quality and ethics as the 2020 decade comes to a close. In May 2018, KPMG was accused of being "complicit" in signing off Carillion's "increasingly fantastical figures" before Carillion ultimately collapsed. In January 2020, PwC faces allegations of potential conflict of interest in its audit of Sonangol, given its dual roles of both auditor and consultant. In September 2020, Deloitte was fined £15 million (US$19.4 million) by the FRC for failing to apply sufficient professional skepticism in its audits of Autonomy's 2009 to 2011 financial statements prior to Autonomy's acquisition by Hewlett-Packard. In June 2020, EY was accused of poor auditing for failing to discover that €1.9 billion in cash was missing at Wirecard AG, precipitating Wirecard's collapse and eventual sale to Santander Bank for €100 million in November 2020. Tax avoidance According to Australian