We show that in the presence of non-zero pricing errors, the Fama–MacBeth (FM) cross-sectional regression test is very likely to either reject the Capital Asset Pricing Model (CAPM) when it (almost) holds or accept the model when it grossly fails. We investigate the case when pricing errors...

We investigate the relationship between changing correlation structure of returns, security risk, and mean return. According to our results, securities that were highly correlated with the market-wide risk factors in the past are likely to have high systematic and idiosyncratic risk at present....