Explore the tradeoff theory of optimal capital structure with taxes and bankruptcy costs
Theoretical Framework
MM Proposition I: No Taxes
VL = VU (Firm value is independent of capital structure)
In a perfect market with no taxes, the total value of a firm is determined solely by its operating cash flows, not how it finances them. Leverage is irrelevant.
MM Proposition I: With Corporate Taxes
VL = VU + t x D (Leverage creates value via tax shield)
Interest is tax-deductible, so debt financing creates a tax shield worth t times the amount of debt. Firms should be 100% debt-financed to maximize this benefit (unrealistic).
MM Proposition II: Cost of Equity Rises with Leverage
re = r0 + (r0 - rd) x (1-t) x (D/E)
As debt increases, equity becomes riskier and more expensive. The increase in cost of equity partially offsets the benefit of cheaper debt, so WACC declines but doesn't fall as fast as with MM Prop I alone.
Tradeoff Theory: Optimal Capital Structure
VL = VU + PV(Tax Shield) - PV(Distress Costs)
In reality, bankruptcy is costly. Firms balance the tax benefit of debt against the expected cost of financial distress. An interior optimum emerges where the marginal tax benefit equals the marginal cost of distress.
Interactive Analysis
Levered Firm Value
$1,250M
Distress Cost (Expected)
$0M
Interpretation: The levered value includes the tax shield benefit. As you increase the probability of distress, the expected cost rises, reducing optimal firm value. There's a tradeoff between maximizing the tax benefit and minimizing distress risk.
Firm Value vs Leverage Chart
Shows how firm value and WACC change with debt level under different scenarios