It's often claimed that some firms delisted from the US market because of Sarbanes-Oxley. But a new study says that's not true.

The Fisher College of Business study, Why do foreign firms leave US equity markets?, found that foreign companies got hammered when they left the US market. And there was no impact from Sarbanes-Oxley. There was no significant evidence showing that deregistering firms had worse stock price reactions to SOX announcements than benchmark exchange-listed foreign firms. There was no SOX effect. But the researchers did find evidence that deregistering firms had worse growth prospects than other foreign firms with exchange listings and that those deregistering firms performed poorly prior to them announcing that they were leaving. All of which says there were other reasons for their decision.

The only qualification to the study is that the sample included only 59 firms. Still, it does raise points to consider.