There's a very important phenomenon that you need to take into account when you look at these histories of returns that are generated by active managers.

当查阅这些主动管理型基金经理,留下的历史收益记录时,有个很重要的现象

耶鲁公开课 - 金融市场课程节选

As reported contemporaneously in 2000,the number was -3.1% but if you look at the number reported for 2005, because bad records had disappeared and good records had been added, all of a sudden the average experience for that year went up to +1.2%.

000年期的公告中这个数字为负3.1%,但是如果你去查2005年公告的数字,坏记录已经调整而消失,有利的投资记录被加入,转瞬之间,年平均收益升至1.2%

耶鲁公开课 - 金融市场课程节选