The risk-aversion coefficient (λ ) characterizes the expected risk-return tradeoff.
It is the rate at which an investor will forego expected return for less variance. In the
reverse optimization process, the risk aversion coefficient acts as a scaling factor for the
reverse optimization estimate of excess returns; the weighted reverse optimized excess
A STEP-BY-STEP GUIDE TO THE BLACK-LITTERMAN MODEL 4
returns equal the specified market risk premium. More excess return per unit of risk (a
larger lambda) increases the estimated excess returns.5