Profit Persistence in the U.S. Audit Market
利用审计公司实现率的专有数据，研究发现美国四大审计业务中存在持续的超额利润，且利润持续性与审计工时负相关、与审计质量正相关，表明低竞争可能带来更高效有效的审计。
ABSTRACT This study investigates the relation between audit competition, audit quality, and auditor labor hours. Using proprietary data on auditor realization rates, we construct new measures of competition based on theory predicting that abnormal profits will quickly disappear when competition is high but persist over multiple periods when competition is low. We find consistent evidence of persistent abnormal profits among U.S. Big 4 engagements and that individual offices earn persistent abnormal returns, suggesting that the market is not perfectly competitive. Examining the consequences of lower competition, we find that profit persistence is negatively related to audit hours and positively related to audit quality. Although we are cautious about inferring causality, our findings suggest that lower competition is associated with more efficient and effective audits.