Moreover, compared with the code of ethics of American Institute of Accountants (AICPA), Germany does not allow auditors to participate in the direct recruitment of competitors' customers without invitation. As we discussed in section 2. 1. 1,

Suppose the strict definition of reputation model is that if a high-quality supplier is found to "cheat" customers, it will "punish" customers by reducing the purchase volume.

Germany's restriction on this kind of competition behavior is also a well-known prejudice based on audit theory to find evidence of market share.

To sum up, in Germany, the difficulty of successfully prosecuting auditors and the long-term loss of investors will reduce the guarantee of audit quality.

Similarly, Germany provides us with an opportunity to clearly test the importance of the theoretical basis known for audit quality. However, due to the small role of auditors in group-led competition and the restrictions of the system, as the evidence can prove, the environmental background in Germany has caused obstacles to finding evidence with consistent theory and famous quality.