5. Conclusions
In this study, we examined the influence of a firm’s main competitor, customer and supplier on the choice for a Big4 auditor. While most auditor choice studies keep relying exclusively on the agency theory to explain this choice, we provide an additional perspective to the extant literature by examining auditor choice from an institutional theory view. The institutional theory states that firms may become very similar to one another as a response to uncertainty, pressures from stakeholders, external expectations, etc. (DiMaggio and Powell, 1983), which is called institutional isomorphism. Therefore, the choice of a Big4 auditor may be a response to one of their main stakeholders hiring a Big4 auditor, irrespective of the level of agency conflicts, because this is considered to be good practice and might therefore increase the firm’s overall legitimacy. Han (1994) already examined isomorphism toward competitors regarding auditor choice in a listed firm context and found that listed firms often imitate the leader of an industry by choosing the same auditor. We add to this study in two ways. In the first place, we examined whether isomorphism may also explain auditor choice in private firms. Second, while Han (1994) only focused on isomorphism toward competitors, we also examined isomorphic behavior toward suppliers and customers.