Labor supply and accounting firm mergers

Abstract

In this paper, I study how regulation-induced accounting labor supply shocks affect the audit market. Using a novel dataset that includes both large and small accounting firms, I identify labor supply shocks using the 150-Hour Rule and the Mobility Provision and investigate the resulting incidence of mergers and acquisitions (M&A). I find that a reduction in labor supply increases accounting firms' M&A activity and leads to a higher audit market concentration. My results suggest that accounting firm growth decisions and audit market structure depend on the supply of labor.