Duke economist: Oops, 50 years of bad analysis

[Northerly]

"Harvey’s work offers another lesson to would-be investors: Even if a fund does consistently beat the market, it may just be a coincidence. With so many investment funds out there, some will overperform in a way that seems statistically significant just by chance."

Apparently if you are an economist at Duke, this is news to you. And you can then write a journal article about this, ahem, discovery.
http://www.slate.com/articles/business/moneybox/2014/11/duke_economist_campbell_harvey_most_research_on_why_investments_do_well.html

[nereo]

this is probably just the nerd in me, but all i can think of when I read that column is "eee!  another person who doesn't get what a p-value or confidence interval really is!"
no wonder there is so much confusion and distrust.