Using hundreds of significant anomalies as testing portfolios, this paper compares the performance of major empirical asset pricing models. The q-factor model and a closely related five-factor model are the two best performing models among a long array of models. The q-factor model outperforms...

We take a simple q-theory model and ask how well it can explain external financing anomalies, both qualitatively and quantitatively. Our central insight is that optimal investment is an important driving force of these anomalies. The model simultaneously reproduces procyclical equity issuance...

We propose a simple methodology to evaluate a large number of potential explanations for the negative relation between idiosyncratic volatility and subsequent stock returns (the idiosyncratic volatility puzzle). We find that surprisingly many existing explanations explain less than 10% of the...