In an article of that title, my friend Emory law professor Bill Carney writes:
The Sarbanes-Oxley Act of 2002 added numerous costs to the burden of being a public company. The most onerous of these, requiring inside and outside assessment of internal controls, is only now affecting the costs of remaining a public company. After reviewing the reports of increased compliance costs for larger companies, this paper reports on the increasing numbers of companies choosing to terminate reporting under the securities laws, and focuses on the costs reported for those (generally smaller) companies that disclose their actual compliance costs.
