Are Cramer's stock picks five percentage points worse than the market?

One of the most interesting parts of the Barron's article is its suggestion that there might be leaks. That's because Barron's found that "stocks Cramer picks as Buys have been rising versus the market for several days in advance of his show, while his Sells have been falling." Using data from the last seven months, Barron's quantified this "leakage effect" -- Cramer's buys had risen 4% against the S&P in the two weeks ahead of his recommendation, while his Sells had dropped more than 7%.

These observations will probably do nothing to distract attention from Cramer and his popularity. I would never expect anyone to be able to beat the market consistently with so many public stock picks, so Cramer's apparent inability to do so is not a big surprise.

But Barron's evidence of leakage does raise questions about whether someone is front-running Cramer's picks.

Peter Cohan is president of Peter S. Cohan & Associates. He also teaches management at Babson College. His eighth book is You Can't Order Change: Lessons from Jim McNerney's Turnaround at Boeing.