The original study has some methodological flaws, and there has been a more recent study that found the opposite. https://papers.ssrn.com/sol3/papers.cfm?abstr

The original study has some methodological flaws, and there has been a more recent study that found the opposite. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3882214 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3882214 So it's far from a settled question.