theorem effectiveMultiplier_zero_at_critical {J : ℕ} {ρ : ℝ}
{T Tstar d_sq : ℝ} (hTs : 0 < Tstar) (hT : Tstar ≤ T) :
effectiveMultiplier J ρ T Tstar d_sq = 0 := by
simp only [effectiveMultiplier]
rw [effectiveCurvatureKeff_above_critical J ρ T Tstar hTs hT, zero_mul]Macroeconomic Applications of the CES Potential