MIMETIC ISOMORPHISM AND ITS EFFECT ON THE AUDIT SERVICES MARKET

A dynamic of imitation among client firms produces the high level of isomorphism observable in their auditor selection. However, the form and extent of a corporate actor's behavior are influenced by the actor's position among competing peers. Examining 2,285 auditor-client pairs, this study finds that the likelihood of imitation in auditor selection systematically varies across the status dimension. First, the leaders in an industry seek to differentiate themselves from their chief competitors. Second, the firms of the middle stratum imitate the leaders in their industry extensively by choosing from the same set of auditors. Third, the firms at the bottom seem to be excluded from this concern. This interplay between inclusion and exclusion among socially differentiated actors, in turn, yields substantial polarization in size among CPA firms and hence the extreme market share concentration that characterizes the audit services market.