In asset pricing, estimation risk refers to investor uncertainty about the parameters of the return or cashflow process. We show that with estimation risk the observable properties of prices and returns can differ significantly from the properties perceived by rational investors. In particular,...

It has become standard practice in the cross-sectional asset-pricing literature to evaluate models based on how well they explain average returns on size- and B/M-sorted portfolios, something many models seem to do remarkably well. In this paper, we review and critique the empirical methods used...

Recent studies suggest that the conditional CAPM might hold, period-by-period, and that time-varying betas can explain the failures of the simple, unconditional CAPM. We argue, however, that significant departures from the unconditional CAPM would require implausibly large time-variation in...

The efficient markets hypothesis has dominated modern research on asset prices. Asset prices and their intrinsic values differ in inefficient financial markets but difficulties in the measurement of intrinsic value greatly complicate market efficiency tests. Reflections on the measurement of...

These notes discuss three aspects of dynamic factor pricing (i.e., APT) models. The first one is that diversifiable idiosyncratic risk is unpredictable in a no-arbitrage world. The second feature is that the conditional factor loadings or betas on the common factors are approximately constant...