According to Kolari, Liu, and Huang (KLH) (2021), zeta risk (denoted by Z^∗_{i ,a}) in the ZCAPM can be positive or negative in sign. Illustrate this two sided zeta risk in a diagram with the ith asset’s excess returns denoted R_i−R _f on the Y-axis and average excess market returns denoted R_a − R _f on the X axis. In your diagram, what is beta risk? Show how positive and negative zeta risk affect the excess returns of assets.