The asset pricing models imply that the expected returns of securities are related to their sensitivity to changes in the state of the economy. Sensitivity is measured by the securities “beta” coefficients. For each of the relevant state variables, there is a market wide price of beta measured in the form of an increment to the expected return (a “risk premium”) per unit of beta. In such a model, the predictable variation of returns can be driven by changes in the betas and changes in the price of beta. Previous studies have identified state variables that are “priced”, in the sense that the risk premiums are different from zero on average. Much research has examined the time-series behavior of betas, but the time-series behavior of the risk premiums has received relatively little attention.