Corporate Finance Week 8 — Capital Structure (MM → Real-World Optimization)

1) What Week 8 is really testing

2) MM baseline (perfect markets): what you must be able to state and use

MM irrelevance conditions (logic, not just list)

Proposition I: capital structure irrelevance

VU = VL (= EL + DL)

Intuition: financing splits the cash-flow “pie” but does not change its size; arbitrage enforces the equality.

Proposition II: leverage raises equity risk/return; WACC constant in MM world

rE = rA + (D/E) * (rA - rD)

Exam trap: “More debt lowers WACC because debt is cheaper.” In MM, that is false: rE rises to offset, so WACC stays constant.

3) Relaxing assumptions → an optimal capital structure exists

Week 8 sets up a checklist for any leverage/capital-structure question:

A) Taxes: why debt can add value

VL = VU + PV(Tax Shield)

Common simplification (when debt is treated as roughly constant): PV(TS) is approximately tax rate × debt value, but this is an approximation and not fully realistic for long horizons.

Exam trap: inconsistent tax treatment (e.g., mixing after-tax WACC adjustments incorrectly). The course logic: start with MM, then add the tax wedge explicitly.

B) Financial distress costs: why 100% debt is not optimal

Static trade-off structure to write in exams:

VL = VU + PV(Interest Tax Shield) − PV(Expected Distress Costs)

Distress checklist (what to discuss)

C) Transaction costs

4) Agency costs + corporate governance (Week 8 “Part 2”)

The core agency problem

Typical agency behaviors to cite

How governance reduces agency costs (mechanisms to name)

  1. Incentives / compensation alignment
    • Restricted stock/options
    • Pay-for-performance
  2. Monitoring
    • Independent directors on the board
    • Large blockholders
    • Market for corporate control (takeovers)

Transcript reinforces that board oversight can fail (high-salience example used to illustrate weak diligence/monitoring).

Debt as a governance tool (agency benefit of leverage)

But excessive leverage creates agency conflicts with creditors (agency costs of debt)

Takeaway: leverage can reduce some agency problems, but too much leverage creates new ones; covenants mitigate many.

5) Asymmetric information: pecking order and market reactions

Pecking order rule (write cleanly in exams)

  1. Retained earnings
  2. Debt (unless already highly leveraged)
  3. Equity as last resort

Pecking order implications

6) “So what’s the number?” — answering practical leverage questions

No one-size-fits-all: you must state trade-offs and justify a range.

Fast-growth vs mature firms (exam-friendly classification)

7) How this shows up on the final: marking-friendly structure

  1. Name the theory (MM / trade-off / agency / pecking order / governance).
  2. Mechanism (tax shield vs distress; debt discipline vs risk shifting; equity-issuance signal).
  3. Prediction (move toward/away from leverage; price reaction; covenant/monitoring changes).
  4. Implication (direction for firm value/WACC; stakeholder impact; governance risk).