中文摘要：

文章以出具“非标意见”概率和操控性应计利润作为审计质量的替代变量，采用Heckman二阶段回归纠正自选择偏差方法，对国际“四大”与审计质量的关系进行了实证研究。结果显示，在控制自选择问题后，国际“四大”与本土事务所出具“非标意见”的概率无显著差异。但与本土事务所相比，由国际“四大”审计的公司操控性应计利润显著更小；在区分操控性应计利润的方向后，由国际“四大”审计的公司正向操控性应计利润显著更小，负向操控性应计利润则与本土事务所无显著差异。这表明与本土事务所相比，国际“四大”在国内市场确实能够提供更高的审计质量，且这种差异主要体现在对正向盈余管理的制约上。

英文摘要：

Employing the probability of the issuance of qualified opinions and discretional accruals as the proxies for audit quality, this paper empirically exam- ines the relationship between audit quality and international big four accounting firms by using Heekman＇s two-stage regression self-selection bias correction method. The empirical result shows that there is no significant difference in audit opinions between international big four and local accounting firms after the control of self-selection. But compared to local accounting firms, discretional accruals of firms audited by international big four accounting firms are significantly smaller. After distinguishing the directions of discretional accruals, positive discretional ac- cruals of firms audited by the big four are significantly smaller, and there is no significant difference in negative discretional accruals. It concludes that compared to local accounting firms, international big four accounting firms actually provide higher audit quality for domestic market, and the difference between them is em- bodied in restrictions on positive earnings management.