I think, there were probably problems with show business where producers and directors would try to get the writing credit also. So they created a rule where the bar, to get your name added to the writing credits, if you've done a revision, is very high if you're also the producer or director.
Eugene Fama
People would be a lot more skeptical if they understood that there is an incredible amount of chance in the results that you observe for active managers. The distribution of outcomes is enormously wide-but that's exactly what you'd expect by chance with lots of active managers who hold imperfectly diversified portfolios. The really good portfolios contain a lot of really lucky picks, and the really bad portfolios contain a lot of really unlucky picks as well as some really bad ones.
