The document discusses the Big 4 accounting firms - Deloitte, PricewaterhouseCoopers, Ernst & Young, and KPMG. It provides details about each firm such as their headquarters location, year founded, number of countries and employees, and revenue in 2015. It notes that until 1989 there were the Big 8 accounting firms, which consolidated to the Big 5 in the 1990s, and then to the Big 4 in 2002 after Arthur Andersen dissolved following the Enron scandal.