Auditor size and audit quality

Regulators and small audit firms allege that audit firm size does not affect audit quality and therefore should be irrelevant in the selection of an auditor. Contrary to this view, the current paper argues that audit quality is not independent of audit firm size, even when auditors initially possesses identical technological capabilities. In particular, when incumbent auditors earn client-specific quasi-rents, auditors with a greater number of clients have ‘more to lose’ by failing to report a discovered breach in a particular client's records. This collateral aspect increases the audit quality supplied by larger audit firms. The implications for some recent recommendations of the AICPA Special Committee on Small and Medium Sized Firms are developed.