SLIDE 19 Iso-Innovation
However, (17) is a transcendental equation. So, the equilibrium innovation rate ¯ g must be solved numerically. More importantly, this equation implies a strictly quasi-concave ”iso-innovation” curve on the support of (δ, θ) in the positive quadrant of R2
+, as given below:
h(δ, θ | ¯ g > 0) ≡ θ ·
g]
ρ + (1 + ψ)¯ g
L − (1 + ψ)a¯ g
(18) The iso-innovation curve characterized by the equation of h(δ, θ | ¯ g > 0) = 0 satisfies:
(i) ∂θ
∂δ < 0 for δ, θ ∈ (0, ∞), ∂θ ∂δ = 0 for δ → ∞, and ∂θ ∂δ → ∞ for
δ → 0; (ii) θ → θmin ≡ a[ρ+(1+ψ)¯
g] L−(1+ψ)¯ g
> 0 for δ → ∞; and (iii) θ → ∞ for δ → 0+.
Hwan C. Lin (UNC Charlotte) Amortizing Securities June 28, 2019 19 / 27