Most of the literature on the relationship between corporate governance and audit fees concentrates on one
or more aspects of corporate governance, such as ownership, board of director or management characteristics,
as proxy variables for corporate governance (Pan, 2008). Although the use of such proxies renders it easy to
collect and treat data, it has a number of disadvantages. For example, it introduces the possibility of omitted
variables in the models because all corporate governance characteristics are not included. In addition, different
characteristics may interact with one another in a manner too complex to identify, thus producing possibly
biased results. Finally, as the influence of single characteristics on the level of corporate governance is uncertain,
it is doubtful whether a proper corporate governance proxy exists. For example, some scholars believe
that CEO duality impairs corporate governance, whereas others take the opposite view. It is thus clear that
identifying the relationship between audit fees and corporate governance on the basis of such a proxy is problematic,
although a more comprehensive corporate governance variable would mitigate or eliminate such
problems to a considerable extent.