Appendix
Proof of lemma 3 Define xbr (π) as the level of environmental regulation such that (2) holds
as an equality:
xbr (π) =
[Γ — ∆θ(p + τ)] πa — λτ∆θ(1 — π(1 — a))
(1 — π)(1 — λ)τ
(3)
Let ∆θ = θR— θI. By inspection of (3), br (π) < 1 if and only if Γ < Γ1(π) ≡ ∆θ(p+τ(1+λ))+
(∆θτ(1—π)∕πα) and br(π) > 0 if and only if Γ > Γo(π) ≡ (p+τ)∆θ+(∆θλτ(1—n(1—a)))∕πa.
Notice that since λ ∈ (0,1), Γo (π) < Γ1(π). ■
Proof of proposition 1 Let H1 = ∆θ(p+τ(1 — λ)) and H2 = ∆θ(1 — a)(p+τ(1 — λ)) +aΓ
where ∆θ = θR — θI. If managerial entrenchment is to be countered, shareholder value writes
as
Vsh(Xr(π)) = ( θI + nA* ) (Hi — πH).
∆θ(1 — π)
The first order condition for shareholder value maximization is given by
π2∆θH2 — 2π∆θH — (θɪH — ΘrHi) _
∆θ(1 — π)2 = 0'
Solving for π* we obtain
— *
π1,2
1±
Θr a(Γ — ∆θ(p + τ (1 — λ)))
∆θ(aΓ + ∆θ(1 — a)(p + τ (1 — λ)))
if Γ < ∆θ(p + τ(1 — λ)), the discriminant is negative and VS0H (π) > 0, for all π ∈ (0, 1).
In this case shareholders always want to set π as close to 1 as possible. Conversely, if
Γ > ∆θ(p + τ(1 — λ)), the optimal level of corporate governance quality is given by
π* = 1 —
Θr a(Γ — ∆θ(p + τ (1 — λ)))
∆θ(aΓ + ∆θ(1 — a)(p + τ (1 — λ)))
Notice that π* is decreasing both in a and Γ. ■
24