Okay, this is gonna get wonky. Giuseppe Paleologo writes, in a comment to my post on Krugman vs. Chicago,

It is not true that:

“The central empirical prediction of the efficient market hypothesis, as laid out by Eugene Fama at the 1969 annual meeting of the American Finance Association, was that markets would move over time in accordance with the Capital Asset Pricing Model.”

CAPM, and all factor models, are *much* stronger than the EMH, i.e., they imply the EMH, but are not implied by it. CAPM’s predictions are also much, much stronger. This was made abundantly clear by the empirical tests summarized by Fama in survey of the empirical literature in 1970 and 1997. …