theorem dispersion_raises_curvature {ρ : ℝ} {N₁ N₂ : ℕ}
(hρ : ρ < 1) (hN₁ : 0 < N₁) (_hN₂ : 0 < N₂) (h : N₁ < N₂) :
concentrationWelfareCost ρ N₁ < concentrationWelfareCost ρ N₂ := by
simp only [concentrationWelfareCost]
apply mul_lt_mul_of_pos_left _ (by linarith : (0 : ℝ) < 1 - ρ)
-- Need: 1 - 1/N₁ < 1 - 1/N₂, i.e., 1/N₂ < 1/N₁
have h_herf := more_heirs_lower_herfindahl hN₁ h
simp only [bequestHerfindahl] at h_herf
linarithFair Inheritance: Taxing Concentration, Not Transfer