8The tedious full derivation is:

[ ] −1 ( rςφt+1+ς(1−ς)σ2r∕2)1−ρ 𝔼t[u(ct+1)] ≈ (1 − ρ) 𝔼t atee [ ( 2 )1−ρ] ≈ (1 − ρ)−1 𝔼t (atR)1−ρ eςφt+1+ς(1−ς)σr∕2 [ 2 ] ≈ (1 − ρ)−1(atR)1− ρ𝔼t e(ςφt+1+ ς(1−ς)σr∕2)(1−ρ) −1 1− ρ (1−ρ)ς(1−ς)σ2∕2 [ ςφ (1−ρ)] ≈ (◟1-− ρ)-◝(◜atR)-◞e r 𝔼t e t+1 constant <0 ◟---excess retur◝n◜ utility-factor--◞