The public accounting profession plays an important role in the American economy by providing assurance services that enhance the reliability of financial information. The profession faced a crisis of credibility in the early 2000s due to high-profile accounting fraud cases like Enron and WorldCom that resulted in company bankruptcies. Audits are the most common type of attest engagement where auditors provide an opinion on whether a company's financial statements follow accounting principles. Large public companies are required by law to have audited financial statements and internal controls to maintain investor confidence and access to capital markets. Privately-held companies may elect to have audits done to support applications for bank loans.