Audit fee determinants and auditor premiums: evidence from the micro-firm sub-market

Despite the growing literature on the market for audit services, to date no study has examined the determinants of audit fees for the smallest auditees in the market. This study therefore provides some new theory and evidence on the determinants of the audit fees of micro-firms operating in the UK manufacturing sector. A key finding of the study is that in the highly competitive market under consideration, independent small auditees willingly paid a premium to be audited by a mid-tier or a (then) Big Six auditor, with the latter commanding the higher premium. It is concluded that these findings are consistent with Big Six (and, to a lesser extent, mid-tier) auditors commanding a brand premium stemming from the (perceived) higher quality audit conducted by large auditors, for which small firms are willing to pay a premium in order to benefit from associated ‘reputational’ and ‘signalling’ effects. The common finding that the explanatory power of audit fee models declines as a function of firm size is also examined. The empirical analysis confirms this effect, but evidence is offered that, rather than resulting from model misspecification, it is likely that audit prices of the smallest auditees are relatively insensitive to variations in corporate size, which may result from lower incremental economies of scale and minimum pricing.