Asset Pricing Restrictions on Predictability: Frictions Matter

U.S. stock portfolios sorted on size; momentum; transaction costs; market‐to‐book, investment‐to‐assets, and return‐on‐assets (ROA) ratios; and industry classification show considerable levels and variation of return predictability, inconsistent with asset pricing models. This means that a predictable risk premium is not equal to compensation for systematic risk as implied by asset pricing theory. We show that introducing market frictions relaxes these asset pricing moments from a strict equality to a range. Empirically, it is not short sales constraints but transaction costs (below 35 basis points) that help to reconcile the observed predictability with linear portfolio return‐based factor models, and partly with the durable consumption model. Across the sorts, predictability in industry returns can be reconciled with all models considered with only a 25 basis point transaction cost, whereas for momentum and ROA portfolios, up to 115 basis points are needed.This paper was accepted by Wei Xiong, finance.