The audit industry is characterized by extreme concentration among four main firms: Deloitte & Touche, Ernst & Young, KPMG, and PricewaterhouseCoopers. Together, these firms are known as the Big Four. The Big Four handle approximately 98 percent of the audits of large U.S. companies and earn 94 percent of total industry revenue for audit and audit-related services. In terms of the potential agency issues related to audit quality, what is your take on the current structure of the audit industry?