The effect of disclosing audit quality control deficiencies on non-audit tax services: Evidence from Deloitte's 2007 PCAOB Part II inspection report

We examine whether public disclosure of Deloitte 2007 PCAOB Part II report, which identifies quality control deficiencies related to audits of income tax accounts, affects Deloitte's auditor-provided tax services (APTS). Using a difference-in-differences model, we document a 17 percent lower likelihood of Deloitte's audit clients employing APTS relative to clients of other annually inspected firms when the report is made public. We also find that the dampening effect of publicly disclosing the Part II report on Deloitte's APTS is more evident among audit clients paying higher non-audit fees to auditors and those with more complex tax planning. These results suggest that revealing income tax-specific quality control deficiencies prompts audit clients to revise upward (downward) their expected costs (benefits) of perceived auditor independence impairment (knowledge spillover) stemming from APTS. Overall, our study suggests that public disclosure of audit firm-wide quality control deficiencies pertaining to audits of income tax accounts imposes a collateral damage to the inspected firm's non-audit tax services, thereby providing a more complete understanding of the consequences of the PCAOB's communications about quality control deficiencies in Part II reports.