Risk Premium and Risk Price in the Equity Market

The equity premium measures the return obtained by investing in equities in excess of a short-term Treasury bill return. In the last thirty years, the financial literature has proposed various risk models to rationalize the magnitude of this premium, which amounts to an annual 6 % to 8 % for most industrialized countries for the post-war period. We review the various models and explain their increased complexity to capture not only the mean premium but also its variability, its predictability at various horizons and its term structure.