theorem susceptibility_proportional_to_M (M₁ M₂ sig_new T : ℝ)
(hT : 0 < T) (hsig : 0 < sig_new) (hM : M₁ < M₂) :
steadyStateSusceptibility M₁ sig_new T <
steadyStateSusceptibility M₂ sig_new T := by
simp only [steadyStateSusceptibility]
exact div_lt_div_of_pos_right (mul_lt_mul_of_pos_right hM hsig) hTResults 86-92: Endogenous Variance Dynamics