中文摘要：

高估企业的净资产和收益很可能带来高于高估部分价值的诉讼成本，而会计稳健性可以降低企业和审计师事务所的预期诉讼成本。但是，由于审计师的自我满足、动力缺失、不严格的审计程序、对审计客户的信心以及审计独立性的降低，较长的审计任期会造成审计师事务所降低对审计活动的投入，降低审计标准，甚至默许企业管理层更多的随意性判断以及不够稳健的报告政策。而“四大”相对于非“四大”而言，由于“声誉”等预期损失较大，因此在风险控制上更加谨慎，随着审计任期的延长，对客户财务报告要求的稳健程度下降较低。

英文摘要：

Assets and income overstatement may lead to higher litigation costs than the benefits it brings, while accounting conservatism can lower the litigation costs for companies and auditor firms. Due to the self-satisfaction, lack of incentive, unrestrictive auditing procedures, overconfidence in audited firms and reduced auditing independence, auditing inputs will decrease and the standard will be looser as auditing tenure extents. Management is allowed to use more discretions and aggressive reporting policies. While big 4 are more conscious about the expected litigation risks due to their reputation, thus as auditing tenure extents, accounting conservatism is reduced more slowly for firms audited by big 4 than that for non-big 4.