For many years now, we have had an ongoing debate about whether Sarbanes-Oxley is forcing foreign companies to quit US equity markets.

Now we have a new study Why do foreign firms leave U.S. equity markets? An analysis of deregistrations under SEC Exchange Act Rule 12h-6 suggesting that Sarbanes-Oxley has had nothing to do with it.

The bottom line is that since they brought Rule 12h-6, it's been a lot easier for foreign firms to deregister. But in an analysis of 59 companies, the researchers found that the foreign firms that quit the US market had lower returns and fewer growth opportunities. But any impact of Sarbanes-Oxley, they found, was not economically significant. "We do not find any reliable evidence that foreign listed firms suffered from SOX or that SOX had a more adverse impact on deregistering firms," they write.

Still, you can't expect this will be the final word on the matter. Expect this debate to continue for some time.