theorem policy_ineffective_above_critical {J : ℕ} {ρ : ℝ}
{T Tstar : ℝ} (hTs : 0 < Tstar) (hT : Tstar ≤ T) :
effectiveCurvatureKeff J ρ T Tstar = 0 :=
effectiveCurvatureKeff_above_critical J ρ T Tstar hTs hTMonetary Policy and the Liquidity Trap