City-level auditor industry specialization, economies of scale, and audit pricing

We examine the effects of city-level auditor industry specialization and scale economies on audit pricing in the United States. Using a sample of Big N clients for the 2000-2007 period, and a scale measure based on percentile rankings of the number of audit clients at the city-industry level, we document significant specialization premiums and scale discounts in both the pre- and post-Sarbanes-Oxley Act (SOX) periods. However, the effects of industry specialization and scale economies on audit pricing are highly interactive. The negative effect of city-industry scale on audit fees obtains only for clients of specialist auditors. By contrast, clients of non-specialist auditors obtain scale discounts only when they enjoy strong bargaining power, suggesting that auditors are "forced" to pass on scale economies to clients with greater bargaining power.