关键词: 自愿性内部控制审计, 强制性内部控制审计, 审计师更换, 审计费用

Abstract: Based on A-share Chinese listed companies from 2007 to 2016, this paper examines the impact of voluntary internal control audit on audit contract in the change of internal control audit system, and expands the research literature on the economic consequences of voluntary internal control audit. The results indicate that the voluntary internal control audit of listed companies is accompanied by a lower auditor turnover, but after entering the stage of mandatory internal control audit, the once voluntary internal control audit has no significant effect on the stability of audit contract. Although the voluntary internal control audit of listed companies does not significantly  increase their overall audit costs in the current period, the work experience accumulated in the early stage of the voluntary internal control audit of listed companies can significantly reduce the audit burden in the mandatory internal control audit stage. However, the impact of the cooperative relationship established due to voluntary internal control audit on the audit contract is only applicable to the non-big four or high importance customers, that is, local accounting firms may take the initiative to meet the voluntary internal control audit needs of listed companies in order to retain (important) customers. There is no significant difference between the big four and the non-big four and whether the customer is important or not as far as the learning effect of the audit experience accumulated in the past voluntary internal control audit is concerned, which can reduce the audit cost in the stage of mandatory internal control audit to a certain extent.

Key words: voluntary internal-control audit, mandatory internal-control audit, audit switcher, audit fee